15 Nov 2026
The voice of the independent garage sector

No more smokey diesels

A cleaning additive from Liqui Moly is said to restore an engine’s original emission values by regularly adding the product to the fuel tank. Diesel Purge dissolves deposits in the injectors and the fuel system – the main culprit to deteriorating emission values. It is also designed to improve ignition performance of diesel fuel, protect against corrosion and prevent partial-load knocking. When faced with a particularly smokey diesel you can give the engine an instant hit by disconnecting the fuel line and putting the end in the can of Diesel Purge and starting the engine to make it run on pure additive, to achieve the best results. You can also fill up the new diesel filter with the product when a car comes in for a regular inspection so the car runs on additive for the first few minutes. This will remove air out of the new filter and help the vehicle pass the MOT exhaust test too.