The Advantages of Larger Tiresby Richard Rowe
When manufacturers create tires, they do so with the knowledge that not all members of the buying public will have identical needs and desires. Some people want high performance while others want tires that look good or cost the least. But the primary thing that most people care about is that the tire lasts as long as possible. One thing many people do to personalize their vehicle is to install a larger wheel and tire package that eliminates factory compromises for optimal performance.
Most off-road enthusiasts will eventually install taller tires on their trucks for increased ground clearance. This allows them to overcome large obstacles that would otherwise have impacted the bottom of the vehicle, causing it to "high-center," potentially damaging the engine and chassis components.
Installing wider tires is the surest and quickest way to increase traction. The math is simple: if you install eight inch wide tires on a car that previously have only six inch wide tires, then there's 30% more rubber on the road and a corresponding increase in grip. Because they distribute the car's load out over a greater area and have more heat-absorbing mass, a wider tire with the same rubber compound as a narrower one will typically last much longer and be less prone to overheating under extreme conditions.
Track-Width and Centering
Cars that use a wheel and tire package that moves the outside edge of the tire outward will effectively receive an increase in track width. This has two main advantages. The wider track width alone will generally give better grip at the limits of handling, but steering feel and feedback will also improve because of the wheel's increased leverage on steering components. This effect is referred to as "self-centering," and it's what causes a car's steering wheel to return to its neutral position when the driver's hands are removed. More self-centering equates to greater feedback through the steering wheel, which is crucial to performance driving.
Wider tires have another major benefit that escapes the attention of most enthusiasts: even with a standard all-season tread, a wider tire will get almost the same performance as a specialized summer tire but will still perform safely in the rain. This is has always been a failing of specialized performance tires, which have larger tread blocks and fewer water channels to increase the tire's contact patch. This gain is offset somewhat by the larger tire's tendency to hydroplane, but the net effect is a positive one when compared to specialized summer tires.
A taller than stock tire in the same wheel has bigger sidewalls that allow the tread to deflect more. While lateral (side-to-side) deflection is a detriment to handling, longitudinal (front-to-back) deformation results in a flattening-out of the tread. Flatter tread puts more rubber down, which increases traction both on the street and off-road. This effect can be enhanced by removing some air from the tire, in a procedure referred to as "airing down."
Richard Rowe has been writing professionally since 2007, specializing in automotive topics. He has worked as a tractor-trailer driver and mechanic, a rigger at a fire engine factory and as a race-car driver and builder. Rowe studied engineering, philosophy and American literature at Central Florida Community College.