Well 15 bottles of Octane booster will show u a definite difference heh, I have used the injection cleaner myself and honestly I can't tell much diffOriginally posted by activez:Hi, anyone use STP before? How do you find these products, such as the Fuel injector Cleaner, Octane Booster, Oil treatment etc?? I will like to try them... heard dat they are good for both new and old cars...