I find on mine that when the morning commute temps. are in the 50's and the afternoons in the 70's, the MPG makes a nice jump up. In my area, March was warmer than April, and the actual results: March- avg. MPG-45.3 April- avg. MPG 44.3I definetly realize im approaching my maximum potential for fuel efficency. I just remember seeing higher mpg's when the temp was in the 80's. Also yes the 91 ocatane fuel that Id like to test out is E0 100% pure gas. I read somewhere a gm guy saying at 90-100 degree temps the cruze did preform better with 91 fuel. My daily route is 375 miles total and im averaging about 52 mpg a day which is just about my max I think. If you check my fuelly youll notice that on days when the temps are cold and windy with rain im getting high 40's and on days its sunny and warm with temps in the 80's im getting low 50's. Just thought id upload that pic to encourage everyone to do what they can to drive efficiently cause this car has a huge potential for fuel economy. I would like to add one tip on how i achieve such high mpg's and that is keep your cars clean both inside and out everyone knows they run better when they are clean.
From what I see so far in May, I'm expecting at least 46 MPG, I'll be posting monthly results the first week in June.