[LT7A]

As long as your engine makes sufficient torque to push the vehicle so that it's not shifting in and out of overdrive on the highway, you're in good shape. Your tire size is the missing ingredient and is important. The weight of your vehicle and how much in-town driving you do are also important. You do have to have a combination that will get you into your torque curve for start / stop and reasonable acceleration. Or around town will eat up the highway gains.