Tip & How-To about Cars & Trucks
|OEM wheel bolt patterns & specs|
OffsetThe lists of bolt patterns to the right includes OS (offset) information in the last two columns. The offset of a wheel is the distance from the mounting surface of the wheel to the true centerline of the rim. A positive offset means the mounting surface of the wheel is positioned in front of the true centerline of the rim / tire assembly. This in effect brings the tire in to the fender well more. Conversely, a negative offset means the mounting surface of the wheel is behind the true centerline of the rim / tire assembly. This will cause the tire to stick out away from the vehicle.
Dual bolt patterns
More often called "dual drilled", some manufacturers (usually cheaper ones) are building their wheels with two bolt patterns. This expands the number of fitments the wheel applies to. For example, a wheel with a 4-100/114.3 bolt pattern has 8 lug holes and will fit both 4-100mm and 4-114.3mm fitments. Without close examination, certain wheels can be mistaken for dual bolt pattern wheels, as some manufacturers will sometimes add a second set of holes only for aesthetics and weight savigs. The holes are often straight through and have no mating surface for the wheel lug nuts.
CenterboreCenterbore relates to the center hole in the wheel that centers the wheel on the hub of the car. Since most wheels are mass produced, they have a large center bore to accommodate several different vehicles. If this is the case, it is recommended that a hub ring is used. Hub rings are hard plastic or metal ring that fits between the wheel and the vehicle. This centers the wheel perfectly on the hub ensuring that there is no run out when the wheel is installed on to the vehicle. Without hub rings it is possible to get vibrations even if the wheel / tire assembly is perfectly balanced.
Measuring bolt patterns
Posted by johnny... on
Dec 05, 2010 | 1984 AMC American Motors Eagle
Aug 26, 2009 | 1983 AMC American Motors Eagle
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