A high octane, high quality leaded fuel designed exclusively for competition use. The SUNOCO Supreme was the official fuel for all NASCAR events until end of 2006(they are now using the unleaded Sunoco 260GTX). Formulated for racing engines with compression ratios as high as 16:1. It has an additive package designed to keep carburettors and fuel injectors clean at the same time as it controls surface ignition for maximum performance. This clean and fast burning fuel will leave no or little carbon deposits which enables precise engine tuning to maximise power. Well proven in all forms of racing including turbo charged engines. Excellent to blend with unleaded fuels to boost their lead content and octane levels (works much better than using octane boosters).