Tire Aspect Ratios, High-vs-Low Profile, and Straight-line Stability
Assumptions: Same brand & model of tire, same alignment settings on test vehicle, same level of power steering assist, same road test trajectory, same weather conditions, and of course, same driver. Vehicle's cold tire pressure is maintained, to within 1psi, of vehicle mfg placard on door pillar, with both sets of tires.
Differences: 4 High profile(70 series for example) tires are mounted and driven, then, 4 Low profile(50 series) tires are mounted and driven. Maintenance, to within 2% of each other's diameter for speedometer accuracy, is taken into consideration.
Given the assumptions proscribed in the first paragraph: With which set of tires, the high-profiles or the lo-profiles, will the test vehicle..
- Track truer in a straight-line?
- Respond quicker to steering inputs?
- Feel heavier when turning the steering wheel away from center?
- Return the steering wheel quicker to center from turns?