Tires
Tires are an integral part of your car's handling package, and their numerous features can alter the handling tremendously. Things like rubber compound, sidewall stiffness, and tread design all change the characteristics. One of the most frequent things Mustangers do is put fat tires out back and smaller tires up front. Much of this comes from the musclecar era when staggered sizes were cool to have, but mostly we do it because power mods are the first thing we do and traction becomes an important issue.
"More rubber on the road will increase grip, but that's not always a good thing," says Schwynoch. Start by asking yourself if the handling is balanced, or does the car understeer (front loses traction first) or oversteer (rear loses traction first)?
"Let's say a car has the same size tires and wheels all around and the car has been modified slightly so that the handling is pretty neutral," Schwynoch says. "Neutral means that if you corner at 1.0 g and you speed up for a corner that you had been taking at the car's 1.0-g limit and try to take it at 1.1 g, then both ends of the car will lose grip, and the tires at both ends will squeal as the car goes into a four-wheel drift.
"If you increase the rear grip, whether by installing wider tires or by some other suspen-sion change, perhaps the rearend of the car now has the ability to corner at 1.2 g, but the front is still limited to 1.0 g. So, when you enter your usual corner and try to go through at more than 1.0 g, the front tires will lose grip, but since the rearend still has grip, instead of the previous four-wheel drift, the car plows through the corner nose-first.
"At this point, the car is still limited to cornering at 1.0 g, but now the balance of the car has changed from neutral to understeer. Most drivers will think that whatever change was made to the car was bad (and they will swear the car is slower), because it 'made the car understeer.' The fact is, the cornering limit is still at 1.0 g; it's just that the balance of the car changed, as it now has a disproportionate amount of rear grip relative to the front."
Tire stagger aside, the construction of the tire has myriad effects on the handling of your vehicle. Tread compounds, tread patterns, sidewalls and even tire pressures are all things to take into account when looking at improving the handling of your Mustang. The construction of the tire directly relates to its intended use so you need to have a clear idea of what you plan to use the car for in order to make the best choice.