Rislone Hy-per Fuel Octane Booster increases your fuel's octane rating to stop engine hesitation, knock and ping, while also increasing power and performance. The formula works equally well on classic muscle cars, newer, smaller, harder-working engines, off-road and racing applications. The increased octane allows the engine to run optimum spark timing, which not only creates more power, but also, in many engines, reduces emissions and increases fuel mileage. It's also the best insurance against bad gas you can find.