Originally Posted by rmurdoch

I typically run 89 octane most of the time, but in the last 4 months I have used premium most of the time. I have never had a problem running Canadian 89 octane gas, but have had crappy performance from 89 octane Chevron gas bought in Washington state.

A friend of mine just bought a new Mustang GT V-8 pushing 300 hp. It has a 9.8 to 1 compression ratio, versus 10.0 for the Maxima. His drivers manual calls for 87 octane in that car. Why is it so imperative the Maxima run on 91 or higher. Quite frankly I don't buy it. I was told by the stealership, when I bought the car new, to run 1 tank out of 3 on premium in order to keep the fuel injectors cleaner. Is that BS as well?