LogFAQs > #965512336

saspa posted...

So it's like, some octanes are better for some cars, or is it a tiered list where the highest octane is best for all cars. And is it just a matter of putting the right octane means not need to take the car to the garage as much?

Engines are designed to run on a specific octane and only that octane. Look in your driver's manual to figure out what octane you need. Failing to use exclusively that octane can both break your engine and void your engine warranty.

If you modify your engine with a supercharger or something else, it's on you to understand how that changes the fuel requirements.

Vast majority of people only need the regular. If you have a sports car like a Corvette or something you might need premium. Putting premium in a car that wants regular can cause misfires. Gasoline is not a "you get what you pay for" product. Specific octanes have specific uses.