Operation CHARM: Car repair manuals for everyone.

Fuel

Gasoline Octane
It is recommended that gasoline meet specifications which were developed by the American Automobile Manufacturers Association and endorsed by the Canadian Vehicle Manufacturers Association.
Regular Unleaded Gasoline 87 Octane or Higher
If the octane is less then 87, you may get a heavy knocking noise while driving. If it is bad enough, it can damage your engine.