You might save a few pounds compared to forecourt prices - but getting caught could cost you your car.

Wisbech Standard: Police have been dipping tanks to check for red diesel. Picture: Norfolk ConstabularyPolice have been dipping tanks to check for red diesel. Picture: Norfolk Constabulary (Image: Archant)

Officers from Downham Market have seized eight vehicles in their last five shifts after they were found running on red diesel.

The fuel, on which a lower rate of duty has been paid, can only legally be used in some farm vehicles.

Wisbech Standard: Police seized this car after its uninsured driver was found asleep at the wheel. Picture: Norfolk ConstabularyPolice seized this car after its uninsured driver was found asleep at the wheel. Picture: Norfolk Constabulary (Image: Archant)

Police have been pulling over vehicles in the King’s Lynn and Wisbech areas and dipping their tanks to check that they are not running on illegal fuel.

Officers also seized a blue hatchback whose driver was having a nap in a layby with the engine running.

“It’s probably not the best idea to fall asleep in your vehicle on a road in Tilney All Saints with your engine running if you don’t have insurance or a driving license,” one of them tweeted.

“Vehicle seized and driver reported for offences.”