Since I put my rims on, acceleration has been really worn down but I recently filled up with 89 octane and my car accelerates and runs like before w/o the rims which is just what I need. Is it okay to run 89 once in a while?
You can run whatever octane rating you want from the pump and it will not hurt the car. I notice my car seems to run better on 89 as well, a lot more smoother, which is odd when it was designed to run on 87.
