In both old and new engines, impurities in gasoline can cause harmful deposits to form in fuel injectors, intake valves, and combustion chambers – in less than 3,000 miles – and cause:

• Lower gas mileage
• Poor acceleration and lost power
• Hard starts
• Auto ignition (knock and ping)
• Increased exhaust emissions

STP® Complete Fuel System Cleaner – our strongest formula – contains powerful detergents to help remove harmful deposits. One tank treatment helps clean the entire fuel system – including fuel injectors, intake valves and even hard-to-reach combustion chambers – to help optimize engine performance.

Step inside a test facility as we compare two engines. Both were run for the same amount of miles with the same gasoline. Then one engine was treated with STP® Complete Fuel System Cleaner. See for yourself how it can help fight harmful engine deposits to maintain optimum performance.