What Octane Rating fuel (91 or 95) should I use for my 1998 Chevrolet Malibu?
For a Malibu, you should be using the low octane (regular) fuel. Mechanics fix cars. They rarely know the engineering behind them. Different fuel won’t do anything for performance. That is a myth. It won’t even help gas mileage. Cars with high compression ratios need a higher octane gas or else the fuel will detonate in the engine prematurely and you will get knock (sounds like marbles in your engine). Sometimes carbon build up can cause knock in older cars so a step up in octane may prevent knock. I would use low octane gas. If you hear your engine kocking, go a step higher in octane level.
