Research and analysis

Vehicle Market Surveillance Unit: results of the 2023 emissions programme

Published 23 November 2023

Introduction

The Driver and Vehicle Standards Agency (DVSA) has a market surveillance unit, which inspects vehicles, trailers and equipment to make sure they meet safety and environmental standards.

This report sets out the findings of vehicle and component testing during 2023. You can also download the unprocessed raw data for all the tests carried out.

There’s an annex that explains some of the emissions reduction technologies mentioned in the report.

How DVSA selected the sample of vehicles tested

DVSA aims to check a representative selection of the most popular vehicle types used on UK roads. In 2023, we carried out tests on:

• diesel cars
• petrol cars
• light duty vans
• PHEV cars(Plug-in Hybrid Electric Vehicle)
• Hybrid Cars (Self Charging Hybrid)
• heavy goods vehicles (HGVs)
• public service vehicles (PSVs)

The vehicles were chosen based on their UK sales, with other vehicles added in to make sure a wide range of manufacturers were included.

DVSA sourced vehicles from hire fleets or bus operators.

The vehicles were not provided by manufacturers and they could not prepare or modify the vehicles before they were tested.

What tests were carried out

DVSA tested the vehicles to make sure they conformed to European emission standards (as adopted in GB legislation):

• Euro 6 for light duty vehicles
• Euro VI for heavy duty vehicles

The types of tests DVSA carried out depended on the type of vehicle.

Cars and light vans

For all Petrol/Diesel cars, self-charging Hybrid vehicles and light vans, DVSA carried out the following tests:

• Type 1 WLTC in a laboratory
• on-road test - called Real Driving Emissions with cold start (RDE)
• double RDE test back to back at 0°C completed in laboratory

For PHEV Hybrid Cars, DVSA carried out the following tests:

• charge depleting Type 1 test in a laboratory
• charge sustaining Type 1 test in a laboratory
• charge depleting Type 1 test at 0°C ambient in a laboratory
• charge sustaining Type 1 test at 0°C ambient in a laboratory
• on road test charge depleting RDE test with cold start
• on road test charge sustaining RDE test with hot start
• double RDE test back to back at 0°C completed in laboratory

Before carrying out the tests the vehicles:

• were checked for any defects that could affect the emissions control system
• had their fuel drained and replaced with standard laboratory reference fuel

The cars and light vans tested in 2023 were type approved using the Worldwide Harmonised Light Vehicle Test Procedure (WLTP) and Real Driving Emissions (RDE) test and were tested using these regulations.

Type 1 WLTC Test in a laboratory

The vehicle is given a standard pre-conditioning test relevant to its approval. It’s then left in a temperature controlled room so that the whole vehicle including engine oil and coolant is ‘soaked’ to a temperature between 20°C and 30°C (as specified in type approval regulations). Following that the test starts with emissions measured from engine start.

This is a legislative test with limits that a vehicle’s emissions must not exceed.

In the charge sustaining tests on PHEV and Hybrid’s the vehicle is set so that the battery state of charge is maintained during the standard test cycle.

In the case of charge depleting tests on PHEV the standard cycle is repeated several times until the battery charge reaches a determined level and then ends on that cycle.

In relation to PHEV vehicles the weighted result shown for each vehicle is a result of processing both the charge sustain and charge deplete cold laboratory tests data together to produce a combined weighted result. The weighting is based off utilisation factors set in the legislation.

0°C tests in laboratory (WLTP)

This test is carried out on PHEV vehicles only. The vehicle is left in a temperature controlled room so that the whole vehicle including engine oil and coolant is ‘soaked’ to a temperature of around 0°C. The vehicle is then subjected to lab test at the same temperature whilst in charge sustaining mode.

Worldwide Harmonised Light Vehicle Test Procedure (WLTP) tests

WLTP replaced the NEDC test procedure for measuring the official fuel consumption, carbon dioxide (CO2) and pollutant emissions of new cars in September 2017. It became mandatory for all new cars powered by an internal combustion engine by September 2018.

WLTP tests are designed to give a more accurate indication of how much fuel the vehicle will use, and the pollutants emitted during driving.

The WLTP test takes 30 minutes to complete and covers just over 23km with an average speed of 45km per hour and maximum speed of 131 km per hour.

On-road test - Real Driving Emissions (RDE)

This test is carried out on public roads using Portable Emissions Measuring System (PEMS) equipment. This test measures pollutants while the vehicle is being driven.

This test involves driving the vehicle for around 1 and a half to 2 hours over a test route on public roads. The route included urban, rural and motorway driving and tests were carried out during the day in normal traffic conditions.

​​If temperatures drop below 3°C during this test, this is considered ‘extended’ conditions and the emissions results for the test are divided by a factor of 1.6. For transparency reasons in this report ‘raw’ RDE results have not been post-processed and have not had additional factors such as the extended conditions factor applied.

On  PHEV Vehicles two road RDE tests are completed, firstly a charge depleting RDE is carried out from a cold start and secondly a charge sustaining RDE carried out from a hot start.

For NEDC approved vehicles and some WLTP approved vehicles sold before September 2019, this is not a legislative test. For these vehicles, it is an additional test that DVSA carried out to understand how they perform under real world conditions.

RDE Laboratory tests

A double RDE test is carried out using the laboratory dynamometer and the soak and test temperature for both tests is 0°C for all vehicles tested.

On all ICE cars and vans including self-charging hybrids except PHEV vehicles the first RDE cycle is derived from the Road RDE drive pattern for each vehicle and the second RDE is derived from a standard RDE cycle with a more rigorous urban pattern applied.

On PHEV vehicles the 1st test is carried out as charge depleting from a cold start and the second test is carried out as charge sustaining from a hot start, both tests follow the same profiles as the relevant road RDE test carried out on that vehicle.

In all cases these tests are carried out back to back without the ignition/engine being switched off and the second test is started within approximately 30 minutes of the 1st test being completed allowing for any required system checks to be completed.

Heavy goods vehicles (HGVs) and public service vehicles (PSVs)

For HGVs and PSVs, DVSA carried out an on-road test using Portable Emissions Measuring System (PEMS) equipment.

Before carrying out the tests, the vehicles:

• were checked for any defects that could affect the emissions control system
• had their fuel drained and replaced with standard reference fuel

Each vehicle is subject to 2 tests, test 1 has a 10% payload and test 2  has a 90% pay load

Each test involves driving the vehicle for around 2 and a half hours over a test route on public roads. The route included urban, rural and motorway driving and tests were carried out during the day in normal traffic conditions.

​​The emissions measured in these tests are normalised to the laboratory engine test using carbon dioxide as an assessment of the amount of ‘work done’. We use this to calculate mass emissions per unit of energy (measured in kilowatt-hours, kWh).

The results are then compared to the laboratory limit to determine whether it is within the conformity factor specified in legislation.

The conformity factor is the maximum permitted ratio of the normalised test result in g/kWh compared to the emissions limit specified for type approval engine testing.

For HGVs and PSVs, the nitrogen oxides (NOx), hydrocarbons (HC) and carbon monoxide (CO) levels all have a conformity factor of 1.5. This is because:

• this test covers a much wider range of operating conditions than the dynamometer engine test
• real world on-road emissions measurements are subject to greater margins of uncertainty

Where the tests were carried out

Tests were carried out at a selection of commercial emission test laboratories across the UK.

DVSA did not use laboratories that are owned by vehicle manufacturers.

Discussing the results with manufacturers

Where vehicles were found to have performed poorly, manufacturers were given the opportunity to explain the test results and describe the emission control strategies they used.

A summary of these discussions is included in the test conclusions in the results section. They provide insight into why a vehicle may achieve the legal emissions limit when tested on the official test cycle, but may emit significantly higher emissions in other situations.

Results: diesel cars

In this section:

Raw data for diesel car tests

You can download the unprocessed raw data showing the results of each test that was conducted on these vehicles.

Download ‘Car (diesel) data, 2023’ (ZIP, 188MB)

Audi Q5

Vehicle details

Make: Audi

Model: Q5 (2021MY)

Engine and fuel type: 1968cc 100kW Diesel

Transmission: Automatic

Emission standard: Euro 6d AP

Test Reference: 36578

Tested: November 2022

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Audi Q5 was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behaviour of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Audi Q5 tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests: Audi Q5

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban(#/km)	PN (#/km)
WLTC	36.1	10.7	1.4		17.3	28.0	0.447		1.18E+10
Legislative limit	500				80	170	4.5		6E+11

RDE tests: Audi Q5

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)					80				6.0E+11
Road RDE Test 1	237.9			8.3	6.0			1.05E+11	7.17E+10
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				114.4	114.4			9.00E+11	9.00E+11
Lab RDE Test 1	34.8			33.4	15.4			9.30E+09	5.03E+09
Lab RDE Test 1	26.6			28.5	12.1			8.82E+09	5.44E+09

Go back to the list of diesel cars.

Ford Tourneo Custom

Vehicle Details

Make: Ford

Model: Tourneo Custom (2022MY)

Engine and fuel type: 1995cc 125kW Diesel

Transmission: Automatic

Emission standard: Euro 6d AP

Test Reference: 36750

Tested: January 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Ford Tourneo Custom was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behaviour of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Ford Tourneo Custom tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban(#/km)	PN (#/km)
WLTC	19.1	4.2	2.3		9.8	14.0	0.09		2.82E+10
Legislative limit	500				80	170	4.5		6E+11

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				80	80				6.0E+11
Road RDE Test 1	89.0			34.7	15.1			2.60E+11	8.88E+10
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				114.4	114.4			9.00E+11	9.00E+11
Lab RDE Test 1	50.1			18.0	8.8			1.81E+10	6.27E+09
Lab RDE Test 1	37.5			23.7	9.6			2.76E+08	1.85E+08

Go back to the list of diesel cars.

Volkswagen Tiguan

Vehicle details

Make: Volkswagen

Model: Tiguan (2021MY)

Engine and fuel type: 1968cc 110kW Diesel

Transmission: Automatic

Emission standard: Euro 6d AP

Test Reference: 36759

Tested: February 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Volkswagen Tiguan was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behaviour of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Volkswagen Tiguan tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests: Volkswagen Tiguan

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban(#/km)	PN (#/km)
WLTC	12.7	6.0	0.7		29.6	35.6	0.33		4.65E+09
Legislative limit	500				80	170	4.5		6E+11

RDE tests: Volkswagen Tiguan

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				80	80				6.0E+11
Road RDE Test 1	26.4			32.7	17.7			7.17E+09	3.11E+09
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				114.4	114.4			9.00E+11	9.00E+11
Lab RDE Test 1	22.0			54.7	24.7			4.50E+10	1.61E+10
Lab RDE Test 1	5.6			23.4	13.3			6.05E+09	2.39E+09

Go back to the list of diesel cars.

Results: petrol cars

In this section:

Raw data for petrol car tests

You can download the unprocessed raw data showing the results of each test that was conducted on these vehicles.

Download ‘Car (petrol) data, 2023’ (ZIP, 175MB)

Aston Martin DB11

Vehicle Details

Make: Aston Martin

Model: DB11 (2022MY)

Engine and fuel type: 3982cc 393.5kW Petrol

Transmission: Automatic

Emission standard: Euro 6d (AP)

Test Reference: 36796

Tested: December 2022

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Aston Martin DB11 was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Aston Martin DB11 tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests: Aston Martin DB11

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban (mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
WLTC	89.7	13.3	11.3		10.4	23.6	0.58		4.67E+10
Legislative limit	1000	100	68		60		4.5		6.00E+11

RDE tests: Aston Martin DB11

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban (mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				85.8	85.8			9.00E+10	9.00E+10
Road RDE Test 1	54.3			15.5	9.0			1.46E+11	7.60E+10
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				85.8	85.8			9.00E+11	9.00E+11
Lab RDE Test 1	46.8			17.3	8.0			2.85E+11	1.25E+11
Lab RDE Test 1	7.5			9.5	4.1			8.72E+10	4.65E+10

Go back to the list of petrol cars.

Audi A1

Vehicle Details

Make: Audi

Model: A1 (2022MY)

Engine and fuel type: 999cc 81kW Petrol

Transmission: Automatic

Emission standard: Euro 6d (AP)

Test Reference: 36561

Tested: January 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Audi A1 was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Audi A1 tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban(#/km)	PN (#/km)
WLTC	100.0	16.55	15.09		15.43		0.21		7.48E+10
Legislative limit	1000	100	68		60		4.5		6.00E+11

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				60	60			6.00E+11	6.00E+11
Road RDE Test 1	47.2			19.2	8.7			1.45E+11	1.12E+11
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				85.8	85.8			9.00E+11	9.00E+11
Lab RDE Test 1	58.4			20.9	7.8			2.17E+11	1.15E+11
Lab RDE Test 1	9.0			7.5	2.9			4.87E+10	3.47E+10

Go back to the list of petrol cars.

CUPRA Ateca

Vehicle Details

Make: CUPRA

Model: Ateca (2022MY)

Engine and fuel type: 1984cc 221kW Petrol

Transmission: Automatic

Emission standard: Euro 6d (AP)

Test Reference: 36745

Tested: February 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The CUPRA Ateca was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the CUPRA Ateca tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban(#/km)	PN (#/km)
WLTC	165.2	16.0	12.7		7.6		0		1.16E+10
Legislative limit	1000	100	68		60		4.5		6.00E+11

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				60	60			6.00E+11	6.00E+11
Road RDE Test 1	118.3			16.2	6.7			3.79E+10	1.50E+10
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				85.8	85.8			9.00E+11	9.00E+11
Lab RDE Test 1	164.9			16.0	7.0			7.00E+10	2.48E+10
Lab RDE Test 1	44.0			11.2	4.7			5.45E+09	2.83E+09

Go back to the list of petrol cars.

Ford Puma MHEV

Vehicle Details

Make: Ford

Model: Puma MEHV (2020MY)

Engine and fuel type: 999cc 91.9KW Petrol

Transmission: Manual

Emission standard: Euro 6d AP

Test Reference: 36563

Tested: December 2022

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Ford Puma was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Ford Puma tested was non-compliant with its legal emissions performance requirements.

#### WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban(#/km)	PN (#/km)
WLTC	193.3	1.58	0.715		12	13.58	0.128		4.78E+10
Legislative limit	1000	100	68		60	-	4.5		6E+11

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				126	126			9.0E+11	9.0E+11
Road RDE Test 1	90.7			26.5	16.6			4.38E+10	3.56E+10
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				85.8	85.8			9.00E+11	9.00E+11
Lab RDE Test 1	82.1			22.9	10.6			1.29E+10	8.39E+09
Lab RDE Test 1	73.5			8.6	5.5			5.72E+09	4.80E+09

Go back to the list of petrol cars.

Hyundai Tucson

Vehicle Details

Make: Hyundai

Model: Tucson (2021MY)

Engine and fuel type: 1598cc 110kW Petrol

Transmission: Manual

Emission standard: Euro 6d (AP)

Test Reference: 40164

Tested: May 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Hyundai Tucson was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Hyundai Tucson tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban(#/km)	PN (#/km)
WLTC	76.2	11.8	8.5		15.7	27.5	0.1		3.67E+10
Legislative limit	1000	100	68		60		4.5		6.00E+11

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				60	60			6.00E+11	6.00E+11
Road RDE Test 1	46.5			61.0	25.3			5.00E+11	2.68E+11
Road RDE Test 2	92.0			47.5	26.5			1.12E+11	1.78E+11
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				85.8	85.8			9.00E+11	9.00E+11
Lab RDE Test 1	55.2			54.2	23.5			1.87E+11	6.58E+10
Lab RDE Test 1	4.8			37.0	16.7			8.84E+09	5.22E+09

Go back to the list of petrol cars.

Maserati Levante MHEV

Vehicle Details

Make: Maserati

Model: Levante (2022MY)

Engine and fuel type: 1995cc 243kW 10kw EM Petrol

Transmission: Automatic

Emission standard: Euro 6d AP

Test Reference: 36717

Tested: December 2022

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Maserati Levante was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Maserati Levante tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban(#/km)	PN (#/km)
WLTC	349.1	24.4	19.1		12.7	37.1	0.09		3.31E+10
Legislative limit	1000	100	68		60	-	4.5		6E+11

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				85.8	85.8			9.0E+11	9.0E+11
Road RDE Test 1	239.5			7.6	4.4			2.42E+10	1.37E+10
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				85.8	85.8			9.00E+11	9.00E+11
Lab RDE Test 1	197.4			6.9	3.4			1.43E+10	6.96E+09
Lab RDE Test 1	79.6			0.8	0.7			1.68E+09	2.94E+09

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Mercedes Benz A Class

Vehicle Details

Make: Mercedes Benz

Model: A Class (2022MY)

Engine and fuel type: 1332cc 120kW Petrol

Transmission: Automatic

Emission standard: Euro 6d (AP)

Test Reference: 36580

Tested: November 2022

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Mercedes Benz A Class was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Mercedes Benz A Class tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban(#/km)	PN (#/km)
WLTC	50.65	18.56	16.84		16.67		0.372		1.62E+11
Legislative limit	1000	100	68		60		4.5		6.00E+11

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				60	60			6.00E+11	6.00E+11
Road RDE Test 1	39.6			24.8	13.8			3.17E+11	1.86E+11
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				85.8	85.8			9.00E+11	9.00E+11
Lab RDE Test 1	50.9			30.1	11.3			4.53E+11	1.63E+11
Lab RDE Test 1	3.5			22.8	8.3			2.84E+10	2.11E+10

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Mini Cooper

Vehicle Details

Make: Mini

Model: Cooper (2022MY)

Engine and fuel type: 1499cc 100kW Petrol

Transmission: Manual 6 speed

Emission standard: Euro 6d (AP)

Test Reference: 36749

Tested: February 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Mini Cooper was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Mini Cooper tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban(#/km)	PN (#/km)
WLTC	152.5	13.0	11.3		7.1	20.1	0.25		6.89E+09
Legislative limit	1000	100	68		60		4.5		6.00E+11

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				60	60			6.00E+11	6.00E+11
Road RDE Test 1	123.7			10.7	8.3			2.26E+10	3.07E+11
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				85.8	85.8			9.00E+11	9.00E+11
Lab RDE Test 1	150.3			14.6	7.7			2.27E+10	9.53E+10
Lab RDE Test 1	56.9			7.9	5.1			8.27E+09	3.61E+09

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Porsche Macan

Vehicle Details

Make: Porsche

Model: Macan (2022MY)

Engine and fuel type: 1984cc 195kW Petrol

Transmission: Automatic

Emission standard: Euro 6d (AP)

Test Reference: 36752

Tested: February 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Porsche Macan was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Porsche Macan tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban(#/km)	PN (#/km)
WLTC	195.9	9.8	8.398		7.811	17.61	0.343		1.58E+10
Legislative limit	1000	100	68		60		4.5		6.00E+11

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				60	60			6.00E+11	6.00E+11
Road RDE Test 1	90.3			21.3	8.6			1.84E+10	1.02E+10
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				85.8	85.8			9.00E+11	9.00E+11
Lab RDE Test 1	111.8			22.5	10.1			4.40E+10	2.74E+10
Lab RDE Test 1	38.2			16.0	8.6			1.15E+10	1.63E+10

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Volvo XC40 MHEV

Vehicle Details

Make: Volvo

Model: XC40 MEHV (2021MY)

Engine and fuel type: 1969cc 145kW 10kw EM Petrol

Transmission: Automatic

Emission standard: Euro 6d AP

Test Reference: 36453

Tested: January 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Volvo XC40 was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Volvo XC40 tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban(#/km)	PN (#/km)
WLTC	166.2	8.65	6.45		9.76		0.37		2.31E+11
Legislative limit	1000	100	68		60	-	4.5		6E+11

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)	-	-	-	60	60	-	-	6.0E+11	6.0E+11
Road RDE Test 1	237.9			8.3	6.0			1.05E+11	7.17E+10
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				85.8	85.8			9.00E+11	9.00E+11
Lab RDE Test 1	226.9			9.4	5.5			2.43E+11	1.30E+11
Lab RDE Test 1	204.3			12.2	6.5			2.03E+10	1.79E+10

Go back to the list of petrol cars.

Results: light vans

In this section:

Raw data for light van tests

You can download the unprocessed raw data showing the results of each test that was conducted on these vehicles.

Download ‘Light van data, 2023’ (ZIP, 120MB)

SsangYong Musso

Vehicle Details

Make: SsangYong

Model: Musso (2021MY)

Engine and fuel type: 2157cc 133kW Diesel

Transmission: Automatic

Emission standard: Euro 6d AP

Test Reference: 37192

Tested: April 2022

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The SsangYong Musso was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behaviour of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the SsangYong Musso tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban(#/km)	PN (#/km)
WLTC	37.4	24.9	4.6		44.0	79.1	0.38		3.20E+10
Legislative limit	740				125	215	4.5		6.00E+11

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				262.5	262.5			9.00E+11	9.00E+11
Road RDE Test 1	55.1			131.2	63.4			3.28E+10	2.16E+10
Conformity Factor limit				2.1	2.1			1.5	1.5
RDE Legislative limit				262.5	262.5			9.00E+11	9.00E+11
Lab RDE Test 1	43.0			127.9	71.7			1.55E+10	7.70E+09
Lab RDE Test 1	26.8			146.0	62.0			2.35E+09	3.11E+09

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Volkswagen Transporter

Vehicle Details

Make: Volkswagen

Model: Transporter (2022MY)

Engine and fuel type: 1968cc 81kW Diesel

Transmission: Manual 5 Speed

Emission standard: Euro 6d (AR)

Test Reference: 36744

Tested: April 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection
• Laboratory preconditioning
• WLTC test in the laboratory
• RDE On road test
• Double RDE test in the laboratory

Conclusion from tests

The Volkswagen Transporter was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behaviour of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Volkswagen Transporter tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	NOx (mg/km)	NOx Urban (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban(#/km)	PN (#/km)	PN Urban (#/km)	PN (#/km)
Cold test 1	25.30	27.18		46.30	0.36		1.08E+10	9.00E+11	9.00E+11
Legislative limit	740	125		215	4.5		6.00E+11

RDE tests

Test or Pollutant	CO (mg/km)	NOx Urban (mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban(#/km)	PN (#/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)		125	125			6.00E+11	6.00E+1`1	9.00E+11	9.00E+11
Road RDE Test 1	45.9	25.9	17.3			1.83E+10	9.54E+09
Conformity Factor limit		1.43	1.43			1.5	1.5
RDE Legislative limit		178.75	178.75			9.00E+11	9.00E+11
Lab RDE Test 1	30.0	24.9	15.2			1.05E+10	9.11E+09
Lab RDE Test 1	9.8	24.4	14.4			2.15E+10	8.05E+09

Go back to the list of light vans.

Results: plug-in hybrid electric vehicle (PHEV) cars

In this section:

Raw data for plug-in hybrid electric vehicle (PHEV) car tests

You can download the unprocessed raw data showing the results of each test that was conducted on these vehicles.

Download ‘Car (plug-in hybrid electric) data, 2023’ (ZIP, 320MB)

BMW 330e xDrive

Vehicle Details

Make: BMW

Model: 330e xDrive (2022MY)

Engine and fuel type: 1998cc 135kW Petrol 80Kw Electric Motor

Transmission: Automatic

Emission standard: Euro 6d (AP)

Test Reference: 37060

Tested April 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• WLTC Test in the laboratory 0°C

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The BMW 330e xDrive was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the BMW 330e xDrive tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)	PN (#/km)
Charge depleting Cycle 1	0.0	0.3	0.2		0.0	0.0		7.30E+06	9.00E+11
Charge depleting Cycle 2	0.1	0.2	0.1		0.0	0.0		8.70E+06
Charge depleting Cycle 3	249.2	10.3	9.3		3.5	0.0		4.80E+10
Charge sustaining	260.2	15.4	13.7		5.8	0.3		6.00E+10
Weighted results	69.5	4.0	3.5		1.3	0.1		1.50E+10
Legislative limit	1000	100	68		60	4.5		6.00E+11
0°C Charge depleting Cycle 1	0.1	0.9	0.9		0.00	0.0		2.20E+08
0°C Charge depleting Cycle 2	252.9	13.4	11.2		1.5	0.2		2.00E+11
0°C Charge depleting Cycle 3	157.8	2.9	1.9		9.8	0.1		6.90E+09
0°C Charge sustaining	315.4	16.8	13.9		7.1	0.2		2.30E+11

Test or Pollutant	CO2 (g/km)	ECAC (Wh/km)		EAER (km)	EAER City (km)
Charge depleting	16.9
Charge sustaining	185.4
Weighted results	44.3	184.1	51.6		51.1
COC Figure (Declared)	42	180	53		56

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				60	60			6.00E+11	6.00E+11
Road RDE Charge Depleting	149.5			2.4	2.3			3.70E+09	1.80E+10
Road RDE Charge Sustaining	193.5			11.8	9.0			1.10E+10	1.60E+10
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				85.8	85.8			9.00E+11	9.00E+11
Lab RDE Charge Depleting	135.2			3.7	2.6			4.60E+10	5.80E+10
Lab RDE Charge Sustaining	129.7			11.1	7.9			1.80E+10	1.50E+10

Go back to the list of plug-in hybrid electric vehicle (PHEV) cars.

Mercedes Benz E300

Vehicle Details

Make: Mercedes Benz

Model: E300 (2020MY)

Engine and fuel type: 1950cc 143kW Petrol 90Kw Electric Motor

Transmission: Automatic

Emission standard: Euro 6d-Temp (DG)

Test Reference: 36840

Tested: 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• WLTC Test in the laboratory 0°C

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Mercedes Benz E300 was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC Cold and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, the MSU does not have reason to believe that the Mercedes Benz E300 tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)	PN (#/km)
Charge depleting Cycle 1	0.1	0.5			0	0.0		1.0E+08
Charge depleting Cycle 2	10.3	0.4			20.7	0.1		3.8E+08	4.94E+10
Charge depleting Cycle 3	3.5	1.3			8.9	0.2		1.7E+08
Charge sustaining	28.4	3.1			28.1	0.4		4.8E+09
Weighted results	6.9	0.7			9.1	0.1		9.3E+08	5.93E+10
Legislative limit	500	-			80	4.5		6E+11	2.05E+09
0°C Charge depleting Cycle 1	0.1	0.3			0.0	0.0		8.3E+07
0°C Charge depleting Cycle 2	8.0	0.9			77.4	0.01		2.4E+10
0°C Charge depleting Cycle 3	1.9	1.1			10.4	0.0		3.4E+09
0°C Charge sustaining	74.6	4.955			70.1	0.1		1.6E+09

Test or Pollutant	CO2 (g/km)	ECAC (Wh/km)		EAER (km)	EAER City (km)
Charge depleting	21.9
Charge sustaining	143.0
Weighted results	41.8	159.3	43.2		43.8
COC Figure (Declared)	36	175	51		51

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				168	168			9.0E+11	9.0E+11
Road RDE Charge Depleting	41.9			19.2	35.0			8.4E+09	1.4E+10
Road RDE Charge Sustaining	71.3			43.7	43.3			1.4E+09	1.0E+09
Conformity Factor limit				2.1	2.1			1.50	1.50
RDE Legislative limit				168	168			9.0E+11	9.0E+11
Lab RDE Charge Depleting	42.7			61.2	66.7			7.0E+09	7.3E+09
Lab RDE Charge Sustaining	44.2			41.4	35.7			2.1E+10	1.4E+10

Go back to the list of plug-in hybrid electric vehicle (PHEV) cars.

Porsche Cayenne

Vehicle Details

Make: Porsche

Model: Cayenne (2022MY)

Engine and fuel type: 2995cc 2250kW Petrol 100Kw Electric Motor

Transmission: Automatic

Emission standard: Euro 6d (AP)

Test Reference: 36751

Tested: February 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• WLTC Cold Test in the laboratory 0°C

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Porsche Cayenne was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Porsche Cayenne tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)	PN (#/km)
Charge depleting Cycle 1	0.0	0.6	0.5		0.00	0.3		7.20E+07	9.0E+11
Charge depleting Cycle 2	104.4	14.3	13.0		12.0	0.3		1.30E+09	1.4E+10
Charge depleting Cycle 3	245.0	1.1	0.1		2.1	0.4		4.70E+09	1.0E+09
Charge sustaining	245.0	15.8	13.8		6.9	0.4		5.00E+09	1.50
Weighted results	82.57	7.1	6.3		3.8	0.3		1.60E+09	9.0E+11
Legislative limit	1000	100	68		60	4.5		6.00E+11	7.3E+09
0°C Charge depleting Cycle 1	142.2	31.5	28.4		5.1	0.0		3.50E+10	1.4E+10
0°C Charge depleting Cycle 2	161.5	12.0	10.3		2.7	0.2		2.00E+09
0°C Charge depleting Cycle 3	228.3	0.8	0.0		1.9	0.0		1.70E+09
0°C Charge sustaining	361.5	26.89	23.7		8.5	0.2		5.80E+10

Test or Pollutant	CO2 (g/km)	ECAC (Wh/km)		EAER (km)	EAER City (km)
Charge depleting	7.4
Charge sustaining	220.3
Weighted results	64.03	263.2	43.1		46.6
COC Figure (Declared)	71	251	44		48

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				60	60			6.00E+11	6.00E+11
Road RDE Charge Depleting	203.7			2.1	4.2			3.70E+09	1.90E+10
Road RDE Charge Sustaining	245.5			6.8	5.7			1.70E+10	2.00E+10
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				85.8	85.8			9.00E+11	9.00E+11
Lab RDE Charge Depleting	292.0			11.5	5.6			3.70E+10	1.60E+10
Lab RDE Charge Sustaining	172.0			7.2	5.3			1.50E+10	1.30E+10

Go back to the list of plug-in hybrid electric vehicle (PHEV) cars.

Range Rover Vouge P400E

Vehicle Details

Make: Range Rover

Model: Vogue P400E (2021MY)

Engine and fuel type: 1997cc 221kW Petrol 105Kw Electric Motor

Transmission: Automatic

Emission standard: Euro 6d (AP)

Test Reference: 36658

Tested: January 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• WLTC Test in the laboratory 0°C

• RDE On road test

Conclusion from tests

The Range Rover Vogue was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Range Rover Vogue tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
Charge depleting Cycle 1	107.74	15.61	14.2		5.6	0.2		3.70E+10
Charge depleting Cycle 2	120.25	13.42	10.7		6.4	0.2		1.40E+10
Charge depleting Cycle 3	178.02	0.5	0.1		6.7	0.5		1.10E+10
Charge sustaining	277.0	7.7	6.0		10.7	0.3		4.10E+10
Weighted results	202.6	10.2	7.8		6.7	0.2		2.70E+10
Legislative limit	1000	100	68		60	4.5		6.00E+11
0°C Charge depleting Cycle 1	403.7	52.5	46.5		12.2	0.1		2.90E+10
0°C Charge depleting Cycle 2	127.3	5.5	4.2		4.5	0.0		2.40E+09
0°C Charge depleting Cycle 3	231.4	1.0	0.2		6.9	0.1		1.40E+10
0°C Charge sustaining	289.4	11.3	9.1		10.5	0.4		6.70E+10

Test or Pollutant	CO2 (g/km)	ECAC (Wh/km)		EAER (km)	EAER City (km)
Charge depleting	24.9
Charge sustaining	264.5
Weighted results	79.6	263.5	37.6		40.7
COC Figure (Declared)	77	260	40		44

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				60	60			6.00E+11	6.00E+11
Road RDE Charge Depleting	169.0			7.7	7.6			1.70E+10	1.80E+10
Road RDE Charge Sustaining	150.0			15.0	15.2			1.60E+10	1.80E+10
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				85.8	85.8			9.00E+11	9.00E+11
Lab RDE Charge Depleting	185.5			12.3	9.0			2.20E+10	2.50E+10
Lab RDE Charge Sustaining	141.9			18.9	11.6			3.50E+10	2.70E+10

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Volvo XC40

Vehicle Details

Make: Volvo

Model: XC40 (2022MY)

Engine and fuel type: 1477cc 132kW Petrol 60Kw Electric Motor

Transmission: Automatic

Emission standard: Euro 6d (AP)

Test Reference: 37057

Tested: April 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• WLTC Test in the laboratory 0°C

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Volvo XC40 was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Volvo XC40 tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)	PN (#/km)
Charge depleting Cycle 1	54.9	5.2	4.4		1.8	0.2		6.90E+09
Charge depleting Cycle 2	49.4	4.3	3.4		4.1	0.2		4.30E+09	1.08E+11
Charge depleting Cycle 3	39.1	1.4	0.4		3.2	1.2		1.40E+10
Charge sustaining	56.6	4.9	4.0		6.3	1.1		2.50E+10
Weighted results	43.1	3.8	3.1		2.7	0.4		1.10E+10	1.86E+10
Legislative limit	1000	100	68		60	4.5		6.00E+11	9.74E+09
0°C Charge depleting Cycle 1	295.2	23.9	19.5		2.4	0.2		4.50E+10
0°C Charge depleting Cycle 2	152.5	14.0	11.7		5.1	0.2		2.10E+10
0°C Charge depleting Cycle 3	42.8	2.1	1.4		5.2	0.5		1.30E+10
0°C Charge depleting Cycle 4	32.5	1.0	0.5		4.4	0.5		1.00E+10
0°C Charge sustaining	138.5	14.4	12.6		6.6	1.0		3.80E+10

Test or Pollutant	CO2 (g/km)	ECAC (Wh/km)		EAER (km)	EAER City (km)
Charge depleting	27.6
Charge sustaining	157.6
Weighted results	49.3	164.7	40.9		54.1
COC Figure (Declared)	49	155	45		52

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				60	60			6.00E+11	6.00E+11
Road RDE Charge Depleting	52.9			0.6	1.7			3.50E+09	1.00E+10
Road RDE Charge Sustaining	42.1			8.7	6.4			9.10E+10	1.00E+10
Conformity Factor limit				1.43	1.43			1.5	1.5
RDE Legislative limit				85.8	85.8			9.00E+11	9.00E+11
Lab RDE Charge Depleting	48.9			0.4	1.3			1.40E+09	9.10E+09
Lab RDE Charge Sustaining	13.7			6.7	6.1			6.40E+09	7.40E+09

Go back to the list of plug-in hybrid electric vehicle (PHEV) cars.

Results: self-charging hybrid cars

In this section:

Raw data for self-charging hybrid car tests

You can download the unprocessed raw data showing the results of each test that was conducted on these vehicles.

Download ‘Car (self-charging hybrid) data, 2023’ (ZIP, 124MB)

Honda Jazz

Vehicle Details

Make: Honda

Model: Jazz (2021MY)

Engine and fuel type: 1498cc 72kW Petrol

Transmission: CVT

Emission standard: Euro 6d (AP)

Test Reference: 37072

Tested April 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Honda Jazz was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Honda Jazz tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
WLTC	50.2	7.22	6.2		2.94	10.16	0.219		2.35E+11
Legislative limit	1000	100	68		60		4.5		6.00E+11

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				60	60
Road RDE Test 1	12.4			3.4	2.0			1.25E+11	4.94E+10
Conformity Factor limit				1.43	1.43
RDE Legislative limit				85.8	85.8
Lab RDE Test 1	63.0			1.8	1.1			1.82E+11	5.93E+10
Lab RDE Test 1	4.0			1.5	1.7			5.76E+09	2.05E+09

Go back to the list of self-charging hybrid cars.

Toyota Corolla

Vehicle Details

Make: Toyota

Model: Corolla (2021MY)

Engine and fuel type: 1798cc 72kW Petrol

Transmission: CVT

Emission standard: Euro 6d (AP)

Test Reference: 36560

Tested: March 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection

• Laboratory preconditioning

• WLTC Test in the laboratory

• RDE On road test

• Double RDE Test in the laboratory

Conclusion from tests

The Toyota Corolla was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (WLTC and RDE).

A number of non-regulatory tests were also conducted to understand if the emissions behavior of the vehicle changed significantly outside of the legislative test, which might be an indication of prohibited emission strategies.

From the results of both legislative and non-legislative testing, DVSA does not have reason to believe that the Toyota Corolla tested was non-compliant with its legal emissions performance requirements.

WLTC lab tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
WLTC	86.6	11.2	9.8		2.3	12.6	0.3		1.78E+11
Legislative limit	1000	100	68		60

RDE tests

Test or Pollutant	CO (mg/km)	THC (mg/km)	NMHC (mg/km)	NOx Urban(mg/km)	NOx (mg/km)	HC+NOx (mg/km)	PM (mg/km)	PN Urban (#/km)	PN (#/km)
COC Figure (Declared Max RDE)				60	60
Road RDE Test 1	33.0			8.0	3.1			3.07E+11	1.08E+11
Conformity Factor limit				1.43	1.43
RDE Legislative limit				85.8	85.8
Lab RDE Test 1	90.3			6.0	2.3			4.96E+10	1.86E+10
Lab RDE Test 1	21.1			18.9	8.0			2.85E+10	9.74E+09

Go back to the list of self-charging hybrid cars.

Results: HGVs

In this section:

Raw data for HGV tests

You can download the unprocessed raw data showing the results of each test that was conducted on these vehicles.

Download ‘HGV data, 2023’ (ZIP, 25.2MB)

Iveco Daily

Vehicle Details

Make: Iveco

Model: Daily N2 Rigid (2020MY)

Engine and fuel type: 2998cc, 132kW Diesel

Transmission: Manual

Emission standard: Euro 6 Step D

Test Reference: 36875

Tested March 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection
• On road conformity test 90% pay load
• On road conformity test 10% pay load

Conclusion from tests

The Iveco Daily was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (On Road Conformity Test).

When the DVSA tested the vehicle to the EU ISC protocol as part of the on road conformity test, they found compliance for THC, CO and NOx emissions. All monitored emissions fell well below the test limits.

From the results, DVSA does not have reason to believe that the Iveco Daily tested was non-compliant with its legal emissions performance requirements.

On Road Conformity Test

Conformity factor result using CO2 window calculation method:

Test or Pollutant	CO	THC	NOx
Legislative Limit	1.5	1.5	1.5
Test 1 90%	0.04	0.00	0.30
Test 2 10%	0.07	0.05	1.07

Conformity factor result using work window calculation method:

Test or Pollutant	CO	THC	NOx
Legislative Limit	1.5	1.5	1.5
Test 1 90%	0.03	0.00	0.22
Test 2 10%	0.06	0.04	1.03

Mercedes Benz Sprinter

Vehicle Details

Make: Mercedes Benz

Model: Sprinter N2 Rigid (2019MY)

Engine and fuel type: 2143cc, 120kW Diesel

Transmission: Automatic

Emission standard: Euro 6 Step D

Test Reference: 37304

Tested: March 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection
• On road conformity test

Conclusion from tests

The Mercedes Benz Sprinter was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (On Road Conformity Test).

When DVSA tested the vehicle to the EU ISC protocol as part of the on road conformity test, they found compliance for THC, CO and NOx emissions. All monitored emissions fell well below the test limits.

From the results, DVSA does not have reason to believe that the Mercedes Benz Sprinter tested was non-compliant with its legal emissions performance requirements.

On Road Conformity Test

Conformity factor result using CO2 window calculation method:

Test or Pollutant	CO	THC	NOx
Legislative Limit	1.5	1.5	1.5
Test 1	0.08	0.00	0.59
Teat 2	0.07	0.00	0.36

Conformity factor result using work window calculation method:

Test or Pollutant	CO	THC	NOx
Legislative Limit	1.5	1.5	1.5
Test 1	0.07	0.00	0.51
Teat 2	0.06	0.00	0.27

Results: Public Service Vehicles (PSVs)

In this section:

Raw data for PSV tests

You can download the unprocessed raw data showing the results of each test that was conducted on these vehicles.

Download ‘PSV data, 2023’ (ZIP, 27.7MB)

Ford Transit

Vehicle Details

Make: Ford

Model: Transit M2 Minibus (2020MY)

Engine and fuel type: 1995cc, 95kW Diesel

Transmission: Manual

Emission standard: Euro 6 Step D

Test Reference: 37074

Tested February 2023

Tests conducted

The following tests were completed on this vehicle to assess the emission control systems and tailpipe emissions:

• Vehicle preparation inspection
• On road conformity test 90% pay load
• On road conformity test 10% pay load

Conclusion from tests

The Ford Transit was compliant with all required tailpipe pollutant emission limits under the applicable legislative test (On Road Conformity Test).

When DVSA tested the vehicle to the EU ISC protocol as part of the on road conformity test, they found compliance for THC, CO and NOx emissions. All monitored emissions fell well below the test limits.

From the results, DVSA does not have reason to believe that the Ford Transit tested was non-compliant with its legal emissions performance requirements.

On Road Conformity Test

Test or Pollutant	CO	THC	NOx
Legislative Limit	1.5	1.5	1.5
Test 1 90%	0.20	0.08	0.79
Test 2 10%	0.32	0.13	0.80

Annex: Emissions reduction technologies

This annex explains some of the emissions reduction technologies mentioned in the report.

Exhaust gas recirculation (EGR)

Exhaust gas recirculation (EGR) displaces intake air with a defined amount of inert exhaust gas. The presence of inert exhaust gas in the combustion chamber reduces both peak combustion temperatures and the amount of oxygen available. This in turn reduces formation of nitrogen oxides (NOx), but can also cause an increase in the emissions of particulate matter (soot).

EGR has been used for many years on both light-duty and heavy-duty engines. Use of EGR may lead to compromises on other vehicle characteristics, such as:

• particulate emissions
• driveability
• fuel economy
• transient performance
• diesel particulate filter (DPF) regeneration interval

However, a well-designed and calibrated EGR system should minimise any negative impacts.

There are a number of types of EGR system available to manufacturers including:

• internal
• external

Cooled internal exhaust gas regulation (EGR)

This occurs within the combustion chamber or exhaust manifold interface, and is set by the timing of the closing of the exhaust valve.

Following the completion of the exhaust stroke, the exhaust valve remains open during the start on the induction stroke, causing some of the exhaust in the exhaust manifold to be drawn back into the combustion chamber. As there is no additional control over this, the amount of EGR that occurs is generally kept low.

External exhaust gas regulation (EGR)

Some of the exhaust gas is directed through a pipe from the exhaust system back into the inlet manifold.

The EGR flow is regulated by an EGR valve, and is set according to a range of engine operating conditions and parameters which are controlled by the electronic control unit (ECU) software and calibration.

High pressure EGR systems take exhaust gas from before the turbocharger. For some Euro 6 vehicles, low pressure EGR systems have been introduced, which takes exhaust gas from after the diesel particulate filter and introduces it into the intake system. Often high pressure and low pressure EGR are used in combination.

Cooled exhaust gas regulation (EGR)

This is the same as external EGR, but the recirculated exhaust gases pass through a cooler before re-entering the engine. This allows EGR to be applied over a wider range of engine operating conditions, and can provide a further reduction in the combustion temperature.

Diesel oxidation catalyst (DOC)

A diesel oxidation catalyst (DOC) promotes the oxidation of several of the exhaust components. These are oxidised using oxygen that is present in the diesel exhaust, in the presence of a catalyst. The components include:

• carbon monoxide, which forms carbon dioxide
• hydrocarbon (HC), which oxidises to become carbon dioxide and water
• soluble organic fraction of particulate matter (SOF)

In addition to targeting regulated pollutants, a DOC can also control several non-regulated HC species, such as aldehydes and polycyclic aromatic hydrocarbons (PAHs), as well as reducing the odour of the exhaust.

DOCs can also oxidise nitric oxide (NO) exiting the engine into nitrogen dioxide (NO2). If a DOC is used on its own, this increase in the more harmful nitrogen dioxide can have a negative impact on air quality. However, generation of NO2 may prove to be a benefit when used prior to a diesel particulate filter (DPF) or selective catalytic reduction (SCR), by helping regeneration in a DPF and enhancing the emissions conversion performance of a SCR.

Diesel particulate filter (DPF)

A diesel particulate filter is a device to trap the particulate matter from the exhaust gas of a diesel engine.

They generally consist of some form of filter material which traps the particles as the exhaust flows through it. During use, soot accumulates in the filter, increasing the back pressure in the exhaust. To allow continued efficient operation, accumulated soot needs to be regularly removed. This can be achieved on the vehicle by a process known as regeneration.

There are a number of ways to achieve this, including:

• increasing the exhaust temperature through engine management (late fuel injection or injection during the exhaust stroke) - diesel particulate burns at about 600 °C, so this temperature needs to be maintained for the regeneration period (for example, a period of higher engine load may need to be sustained)
• adding a fuel borne catalyst, which reduces the combustion temperature of the particulate from 600 °C down to 350 to 450 °C - this requires a small additional tank to hold additive, plus the associated plumbing, but this is more fuel efficient as no additional diesel fuel is required
• passive regeneration – the presence of NO2, generated in the diesel oxidation catalyst (DOC), can also reduce the combustion temperature allowing the DPF to regenerate continuously, avoiding the fuel consumption penalties associated with raising the exhaust temperature to initiate regeneration

The alternative to on-board regeneration is to remove the DPF from the vehicle, though this is often impractical and is not a common solution.

Lean NOx trap (LNT)

Unlike a petrol engine, a diesel engine’s combustion process and exhaust gas is ‘lean’, which means it has excess oxygen present. As a result, a standard diesel oxidation catalyst cannot convert NOx (nitric oxide and nitrogen dioxide) emissions.

A lean NOx trap is a device which looks similar to a standard diesel oxidation catalyst that acts as a molecular sponge, chemically trapping NOx emissions (by adsorption) rather than converting them. They are a type of NOx Storage Catalyst (NSC).

The amount of NOx a trap can hold is dependent on its temperature as well as other constituents such as sulfur. The optimum temperature window is typically around 250 to 450°C. However, once the trap is full, it cannot adsorb any more NOx. The trap must therefore be periodically ‘purged’ by briefly creating ‘rich’ conditions (excess fuel) in the exhaust.

When this happens, the trap releases and simultaneously converts the NOx to nitrogen and water vapour, a process often termed “deNOx”. The frequency with which this happens will depend on the system and the driving conditions, but can be several times an hour.

Selective catalytic reduction (SCR)

Selective catalytic reduction (SCR) is an alternative catalyst system that is able to convert NOx (nitric oxide and nitrogen dioxide) even under ‘lean’ exhaust gas conditions.

The reaction takes place with ammonia (typically supplied as AdBlue) in the presence of a catalyst, which is either oxides of base metals (such as copper, iron, vanadium, molybdenum and tungsten), zeolites, or various precious metals.

To be efficient, the SCR must be at its nominal operating temperature (typically 250 to 450°C) and it can reduce NOx emissions by up to 95%. Critically, unlike the other systems described here, SCR relies on a consumable reagent (that provides the ammonia) and only reduces emissions whilst the catalyst is being supplied or “dosed” with this reagent. Urea has the trade name of AdBlue, and is also known as Diesel Exhaust Fluid (DEF).

As a result, regulations require:

• a visible and audible driver warning when reagent levels are low
• that vehicle performance is restricted or engine restart is prevented if the driver fails to refill the system

The temperature of the SCR is determined primarily by the exhaust gas. Therefore, the placement of the SCR in relation to the engine and the engine’s duty cycle are critical with respect to the SCR’s performance. The SCR canister is relatively large. In addition to the SCR, the following are also required:

• urea/diesel exhaust fluid (DEF) tank - the urea dosing rate will vary by engine and vehicle, but this tank will be sized to avoid vehicle owners having to refill too frequently - the tank also contains heaters and sensors
• a dosing pump to pump the urea from the tank into the exhaust pipe just before the SCR
• a control module to control the amount of urea added
• pre and post SCR NOx sensors to ensure that the SCR system is operating correctly

Although readily available, the main design constraint is the amount of space needed for the installation.

Ammonia catalyst

SCR requires ammonia, which is derived from the urea. The ideal ratio of ammonia to NOx is 1:1.

Under certain conditions, such as low efficiency, extreme low temperature, extreme high temperature, and high mass flow, not all of the ammonia might be used in the NOx reduction process, and some of it may exit the SCR. This is known as ammonia slip.

To prevent the release of ammonia at the tailpipe, an additional catalyst is placed immediately after the SCR. There are various terms for these devices, including:

• ammonia oxidation catalyst (AOC)
• ammonia slip catalyst (ASC)
• clean up catalyst (CUC)

Any ammonia can either be oxidised to NOx, which is not really desirable, or it can be selectively oxidised to produce water and nitrogen. The ammonia catalyst is often packaged in the same can as the SCR.

Combination devices

Almost all diesel engines these days are turbocharged. The resulting emissions will be dealt with using a combination of techniques. This commonly includes:

• exhaust gas recirculation, diesel oxidation catalyst, and diesel particulate filter
• exhaust gas recirculation, diesel oxidation catalyst, lean NOx trap, and diesel particulate filter
• exhaust gas recirculation, diesel oxidation catalyst, selective catalytic reduction, and diesel particulate filter
• exhaust gas recirculation, diesel oxidation catalyst, lean NOx trap, diesel particulate filter and selective catalytic reduction
• exhaust gas recirculation, diesel oxidation catalyst, lean NOx trap, diesel particulate filter, selective catalytic reduction and ammonia slip catalyst

Gasoline particulate filter (GPF)

Gasoline particulate filters (GPF) have been introduced to reduce particle number emissions from gasoline direct injection (GDI) vehicles. The filters use wall-flow substrates that were first developed for diesel particulate filters.

The GPF regenerates passively, but an active regeneration assist is needed to prevent filter plugging during low temperature duty cycles.

Port fuel injection (PFI)

Port fuel injection (PFI) injects fuel into the intake ports just upstream of each cylinder’s intake valve.

The main advantage of PFI when compared to direct injection is the extra time allowed for fuel and air mixing, delivering a more homogenous air and fuel mixture.

Aftertreatment hydrocarbon injector (AHI)

Aftertreatment or auxiliary hydrocarbon injector (AHI) is a fuel injector located in the exhaust upstream of the diesel oxidation catalyst (DOC) and diesel particulate filter (DPF) and is used to assist with raising the DPF exhaust gas inlet temperature when an active DPF regeneration is required.

These systems are typically employed in heavy duty diesel engines.

Three-way catalyst (TWC)

Three-way catalytic converters are effective in preventing air pollution from rich-burn and stoichiometric engines fuelled by natural gas, propane and gasoline. Three-way catalysts are designed to perform multiple oxidation reactions and reduction reactions simultaneously to convert air pollutants that are present in the exhaust to harmless gases.

Exhaust gas composition depends on the air to fuel ratio (AFR) at which the engine operates. Rich mixtures (lambda less than 1) produce high concentrations of nitrous oxides (NOx), carbon monoxide (CO) and hydrocarbons (HCs). The exhaust gases of lean fuel mixtures (lambda greater than 1) contain reduced amounts of NOx and HCs.

The three-way reactions take place over specially formulated precious metal catalysts that allow the reduction of NOx by CO and the oxidation of CO and HC by oxygen to occur simultaneously. The catalyst functions most efficiently when the engine oscillates around the stoichiometric point (lambda equal to 1).

Three-way catalysts are typically used with an air to fuel ratio (A/F) controller to maintain a tight control of air fuel ratio (AFR) around stoichiometry. These controllers use a feedback signal from an oxygen sensor located in front of the catalyst and are required for the three-way catalyst to operate properly.

Carbon dioxide (CO2) reducing technologies

For carbon dioxide (CO2) measurements, there are multiple factors which can contribute to a vehicle’s performance when testing in a laboratory.

These include vehicle-based CO2 reducing technologies such as:

• stop-start system
• electrification or hybridisation
• intelligent battery system management
• gear shift scheduling

Other things that can have an impact are:

• ambient temperature
• road load simulation
• driver dynamicity

NEDC approved vehicles

For vehicles that were approved under NEDC test procedures, CO2 values obtained under type approval test conditions can be challenging to reproduce.

This can be as a result of ensuring any CO2 reducing technologies deployed are operating in their entirety and as designed. As well as replicating to the full extent the boundary conditions under which the vehicle was type approved.

There are many ways manufacturers can follow regulations to optimise CO2 performance under type approval test conditions. Without having the full scope of test set-up and vehicle preparation information, this adds an additional factor of complexity in a third-party test environment.

WLTP approved vehicles

The introduction of the WLTP regulation reduced these possibilities, and we observe this in our emissions test programme, where typically CO2 values declared at type approval can be reproduced relatively easily in the same third-party environment.

Conformity factor

An emissions conformity factor is a ratio of the respective Type 1 laboratory limit value.

For example: for the Euro 6d emission standard, the M1 category WLTC NOx limit for diesel is 80mg/km. The RDE NOx limit is expressed as conformity factor equal to 1.43, so this will be 1.43 multiplied by 80mg/km, giving a limit value of 114.4mg/km.

This is then applied as the respective NOx limit value for RDE testing.