So just an update. I inflated my tires to 40psi, and am getting only slightly better mileage (38.6 v. previous 37.8), but as I said, almost all of my driving is stop and go city driving. The streets in LA suck with all kinds of potholes and the ride is pretty bumpy. it gives me a headache. But the only really annoying problem so far is that my windshield wipers stutter...I know most cars will do this when there isn't much water on the windshield, but my do it in pouring rain. DO you think it's because it's a new car and they just haven't been broken in yet? Or would it be something else?