...using the A/C seems to result in better performance. I have an EX. When it started warming up in June I had need to use the A/C and noticed the car starting from the line and shifting more smoothly. Then I noticed the MPG appeared to go UP!. My regular tracking of my mileage seemed to bear that but I had only been running the A/C about a third of the time. The following two weeks it was much hotter and I left the A/C on all the time. Guess what? The MPG went up again. Originally I was averaging just over 50 MPG. Now, I show an average of 52+.