Instead of the normal P185/65R14 that turn at 902 revs/mile, I tested and fitted P185/70R14, 867 revs/mile . . . about a 6%, permanent overdrive. The mileage remains 52 MPG and handling improved. The larger diameter tires 'track true' at highway speeds versus the 'neutral stability' of smaller diameter tires. At 51 psi, they take curves wicked fast causing tailgaters to back off (and usually left behind.) It also lets the car run in 'hybrid mode' a little faster, keeping up with traffic while getting hybrid mileage. Since I'm into fuel savings, acceleration is not my problem.