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HMRC internal manual

Hydrocarbon Oils Strategy

Introduction: auxiliary engines

Gas oil can be used to power auxiliary engines of vehicles and can therefore be found on the vehicle and at the premises of these businesses:

  • refrigerated transport - fridge unit
  • cleansing lorries - donkey engine
  • fairgrounds - showmen’s’ generators.

They must not however be connected, or be capable of being connected, in any way to the propelling engine and / or its fuel supply.

Note - dual fuel systems, where one engine can be switched from a tank containing gas oil to carry out a stationary application (eg as a gulley emptier) to one containing DERV for road propulsion are not permitted.