Monday, January 5, 2009
BMW wheel bolt pattern
I see a lot of people looking for the BMW bolt pattern. It is as follows:
4 lug -> 4x100mm or 3.937 in. ---> All 4 lug BMW's all years
5 lug -> 5x120mm or 4.724 in. (chevy is very close to this) ---> All 5 lug BMW's all years
A four lug or five lug bolt cirlce is an imaginary circle running through the center of the lug holes. A 4 lug pattern can be measured from center of one lug to the center of the lug diagonally across from it. A 5 lug pattern is much more difficult to measure, due to the fact that the lugs are not equally opposite and would require a bolt pattern gauge.
Offset: The offset is where you run into trouble. The offset of a wheel is as follows: 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 wheel. This will bring the tire in to the fender well more. A negative offset will mean that the mounting surface of the wheel is behind the true centerline of the wheel. This will cause the tire to stick out away from the vehicle..
Most 5 , 6 and 7 series wheels will work on each other.
Early 3 series cars were 4 lug. The 3 series cars that are 5 lug, E36, E46 and E90, have a front wheel drive offset (negative offeset). This pushes the hub portion to the outside edge of the wheel and cause 3 series (5 lug) wheels to not fit on 5, 6 and 7 series cars. The back of the wheel will hit the strut before the hub surface makes contact. The 5, 6 and 7 series wheels will bolt onto a 3 series (5 lug) but tend to stick out and rub on the fenders (posative offset).
Here is a link to a bunch of factory wheels