The four different types of tire bolt patterns are four-bolt, five-bolt, six-bolt and eight-bolt. Some tire manufacturers also make wheels with two different bolt patterns for versatile installation options.
A bolt pattern explains the way the mounting bolts are arranged on a wheel. Each pattern orients the bolts on an imaginary circle that runs around the center of the wheel. A four-bolt pattern has four bolts, each equidistant from the other. The bolts in a five-bolt pattern resemble the five points of a star. The six-bolt and eight-bolt patterns feature six and eight bolts respectively, each situated equal distances apart.
The distance between bolts is an important component of the bolt pattern; all four-bolt wheels are not identical. The manufacturer specifications for a bolt pattern usually include a millimeter measurement. A wheel with a 4-115mm designation has four bolts that are 115 millimeters apart.
When determining the bolt distance, a manufacturer measures from the center of one bolt to the center of the opposite bolt. On a five-bolt wheel, which does not feature opposing bolts, the measurement is different. To get a five-bolt spec, the manufacturer chooses one bolt as the starting point and measures to the bolt that is on the other side of the adjacent bolt.