Gumout's Octane Booster raises the octane level in gas to restore proper combustion and performance. All engines are calibrated to run on fuel with a specific octane rating. If the octane is too low, fuel can ignite early, causing knocks and pings. In vehicles with knock sensors, lower octane gas can retard timing, reducing performance and fuel economy. This Octain Booster is oxygen sensor safe and safe for use in turbocharged and supercharged vehicles. Will not void OEM/manufacturer's warranty. Add entire bottle to nearly empty gasoline tank, then fill tank with up to 15 gallons of gasoline. Use every fill-up.Pack of 6