Amy,

You'll find folks here that run tires at the pressure listed on the sidewall, at 32 psi, and anywhere inbetween. All my tires had a 51 psi max on the sidewall, and I've run them at 45 psi for about 2 years now. Because there are SO many things that can influence your MPG, it's difficult to quantify if, or how much, tire pressure helps. I've found that anything that makes a 0-2 MPG difference is very difficult to detect without some kind of controlled experiment. However, I believe that higher pressure can help. I *feel* like the car rolls better with the higher pressure.

*** Retired after 65,000 outstanding miles ***