STP® Engine Flush is designed to help neutralize harmful engine acids, while it works to loosen and remove sludge, varnish and gum deposits. It also improves lubrication life and protection of new oil. STP® Engine Flush is designed for petrol and diesel engines. How it helps: Loosens and removes harmful sludge and deposits, Thoroughly cleans engine of problematic acids, Frees sticking internal engine components, Ensures new oil remains un-contaminated, Removes dirt and contaminants normal draining leaves behind. Oil Flushing Additive 3 X 450 MLTP Engine Flush 450ml For Petrol Or Diesel Engines Oil Flushing Additive 3 X 450 ML3 x STP Engine Flush 450ml For Petrol Or Diesel Engines Oil Flushing Additive 3 X 450 ML