While on a cross country trip this week I decided to run different octane fuels just to see if there was any noticeable difference. If at all possible I use Exxon fuel and especially on this trip. I used 87, 89 and 93 octane. I noticed absolutely no difference in how it sounded, felt no difference in how it ran. Here is the part of this that really shocked me. After running a tank of 93 until the gas light came on, then ran a tank of 89 til the light came on, then a tank of 87. The tank of 87 octane I got 20.1 mpg! I have not been able to hit 20 again but was shocked it did that and with 87 octane. I get a consistent 15 mixed driving and the only other long trip I’ve taken it on it did 17.2-17.5 consistently. What are you guys seeing out of yours?