STP Complete Fuel System Cleaner Petrol 400ml, to improve engine performance Restores Performance: Specially formulated to help restore your car’s fuel system to optimum efficiency Removes deposits: Just one treatment of this petrol fuel system cleaner dissolves deposits from the entire fuel system Lowers Emissions: This car fuel system cleaner helps reduce exhaust emissions and lower fuel consumption Reduces Hard Starts: A cleaner fuel system can give you a smoother driving experience Quick & Easy: Simply add to your fuel tank every 4000 miles For All Petrol Engines: Suitable for both classic and modern engines, and for catalytic converters