Gum out Regane High Mileage Fuel System Cleaner reduces friction in the upper cylinder to improve fuel economy, while using PEA (polyether amine) to effectively remove deposits other products can't for restored performance. Engines with over 75, 000 miles can suffer from extensive carbon deposits and excess friction. Gum out Regane High Mileage Fuel System Cleaner conditions fuel to fight ethanol and water corrosion, and the upper cylinder to reduce friction and wear. Cleans direct and indirect fuel injectors, intake valves and ports, piston tops, cylinder heads, and combustion chamber, providing restored performance and fuel economy in high mileage vehicles with one fill-up. Also prevents future carbon build-up and reduces emissions. Oxygen sensor safe and safe for use in turbocharged and supercharged vehicles. Will not void OEM/manufacturer's . Directions: Add entire bottle to nearly empty gasoline tank, then fill tank with up to 21 gallons of gasoline. For best results, do not refill tank until near empty. Use every 3, 000 miles.