Aftermarket wheel and tire combinations are one of the most popular choices for the enthusiast looking to upgrade the look of their car, truck, or SUV. However, with so many wheel and tire sizing options many people have trouble getting it just right. Compiled and discussed by our lead technician, here are a few key guidelines to follow when shopping for wheels and tires.

 

When replacing your factory wheels and tires it is always more appealing to 'size up' your wheel and tire combination. A larger wheel/tire diameter fills out the wheel well for a sportier, cleaner look. A wider tire not only increases the effective contact patch on the pavement, but also gives a vehicle a wider, more aggressive stance. Be wary of tire and wheel combinations that are too large! Installing oversized wheels and tires is a dangerous game because without suspension modification, the tire itself can rub on any number of surrounding parts of the car. A tire that is too large in diameter can rub on the edges of the fender well when turning or encountering large bumps or dips in the road. A wheel with an extreme offset or backspacing, or a tire that is too wide can rub on the frame, steering, or suspension components causing premature tire wear or component failure. The desire to 'Go Big or Go Home' can leave you going home in a noisy vehicle with a costly repair bill.

 

In general it is best to stick with a backspacing and offset that closely resembles that of your factory wheel. On passenger cars components such as brake calipers, ABS sensors, and suspension arms come in very close proximity to the inner surfaces of the factory wheel. Installing or attempting to install wheels with a backspacing or offset that is much different from the factory setup can cause the inner surfaces of the wheel to contact these components. Premature wear and failure of these components as well as the wheel itself can occur, as well as an undesireable noise in the passenger compartment.

Wheels manufactured for trucks and SUVs have a much wider offset and backspacing to accomodate larger braking systems, wider wheelbases, and four wheel drive components. It is sometimes popular for truck and SUV enthusiasts to purchase wheels with a significantly wider offset and backspacing for an extremely wide stance. While this can look great and increase the handling of the vehicle it is easy to get carried away. Many people don't realize that this can also cause tire rub. Basically the farther out from the hub centerline that the wheel extends, the wider the arc that is created by the front wheel as it turns from side to side. If this arc is larger than the diameter of the wheel well, the tire will rub on the outer edge of the fender lip or the inner surface of the wheel well liner.

An even less commonly accepted but still important issue can arise with wheels that have an extreme offset and backspacing. The laws of physics tell us that the farther out on a supporting boom a load is extended, the more force is in turn exterted on the fulcrum of the boom itself. As it applies to our conversation this means that the farther out from the wheel hub the weight and body of the wheel extends, the more force is exterted on the hub itself. This can mean damage over time to the lug studs, ball joints, and hub bearings as well as increasing the risk of damage to the wheel.

 

Once you have picked out a wheel and tire combination that works for you, YOU'RE NOT DONE YET! In addition to the basics, there are a few items that you will need to get the job done. The most imprtant item to remember is a set of lug nuts. Sometimes the factory nuts will be compatible with aftermarket wheels, but this is not something you can count on. Factory lug nuts are often too large for aftermarket wheel lug wells, as well as showing an unsightly contrast to a shiny new wheel. There are a myriad of aftermarket lug nut styles available, and you should choose a style that not only works well with your wheel, but also compliments it's looks. Things to keep in mind are thread pattern and thread pitch, socket size, seat style, and overall length. Examples of some common lug nut styles are shown below.

In addition to the necessary hardware there are a few operations that need to be performed on newly mounted wheel and tire packages. Every wheel must be balanced once a tire has been installed on it, new or used. Balancing involves placing weights on the wheel at specific locations to eliminate any difference in the rotational mass of the mounted wheel and tire. Valve stems must also be installed on all wheels before tires can be mounted.