Wheel Fitment Guide
There are many factors affecting which wheels will fit your vehicle. This wheel fitment guide will help you better understand the key factors involved with wheel fitment.
What Is Bolt Pattern?
Bolt pattern, sometimes called lug pattern, is a reference to the number of bolt holes in a wheel and the diameter (measured in inches or millimeters) of an imaginary circle drawn through the center of each lug hole in the pattern. A bolt pattern is vehicle specific, and for most cars, trucks and SUVs, will have 4, 5, 6 or 8 lug holes.
To measure the bolt pattern of wheels with an even number of bolt holes, measure from the center of a bolt hole to the center of the bolt hole directly across from it. To measure the bolt pattern on wheels with an odd number of bolt holes requires a special bolt gauge. You can estimate this distance by measuring from the center of one bolt to the bottom of the area between the two bolts directly across from it (as pictured), but remember this is an estimate, and may not be the exact bolt pattern measurement.
Wheel offset is another important factor in determining wheel fitment. Offset is the distance (in millimeters) between the center line of a wheel (the mid-point between the inner and outer lips) and its mounting surface (where the wheel contacts the drum or rotor). Wheels can have negative offset, positive offset, or zero offset, but most wheels today have a positive offset. The offset determines the proper placement within the wheel well, so a negative offset will move a wheel further out of the wheel well, while a positive offset will move a wheel further in.
Wheel backspacing is the measurement from the back or inside edge of the wheel to the mounting surface (where the wheel contacts the drum or rotor). To measure wheel backspacing, place the wheel face down, then lay a straight edge across the inner lip of the rim and use a ruler to determine the distance between the mounting surface and the straight edge, as shown in the picture below. Wheel backspacing is related to wheel offset, but is not the same thing, as wheel backspacing is the combination of offset and wheel width. This is important when considering wider wheels, as the offset may need to change to maintain proper clearance and avoid rim or tire rub.
Many customers are interested in increasing the size of their wheels, tires, or both. This might mean moving from a 16-inch, 17-inch or 18-inch wheel to a larger 17-inch, 18-inch, 20-inch or larger diameter wheel. This is known as plus sizing or up-sizing, and requires plus sizing tires as well. When plus sizing, it is important to keep the overall diameter of the wheel and tire combination as close to the stock measurement as possible. This is accomplished by choosing a tire with a shorter sidewall (lower profile). If you are interested in plus sizing wheels and/or plus sizing tires, please give us a call and one of our wheel specialists will be happy to help you find the right combination for your vehicle.