Also, since we're on the subject, I've been trying to get the best gas mileage I've ever gotten. It'* 29 mpg. Combined. That'* about 50% city, 50% highway. I got better gas mileage than a Honda Civic
I generally get better than 29... with the current season and with your conditions I'd estimate 32-33 to be par for the course. And that'* with normal driving and a definite lack of maintenance on my part. Pussyfooting/Hypermiling would only mean better
I ALWAYS use Shell V-Power 93 or Sunoco Ultra 94, nothing else.
I had to use Speedway 91 octane one time in a pinch, and it caused me to get KR, I swear it was just 89 with octane booster dumped in the underground tank. BP has also caused problems, half the time the gas smelled weak (stale).