now this is great, i filled up w/ 89 octane and put stp injector cleaner in and now my engine makes rough sounds and even kills sometimes at idle. i think its the octane is too high. whattya guys think. hope it doesnt do much harm tho
well that's a misconception. Higher octane won't damage your car. The only way octane can hurt you is if it's too low. Read this article from the Federal Trade Commission on this subject
