Wheel Fitting – Bolt Pattern & PCD

PCD (Pitch Circle Diameter) is the measurement of the diameter of the imaginary circle drawn through all of the wheel bolts or studs on a wheel.  Some refer to it as the ‘bolt circle’. It is usually measured in millimeters (mm).

A wheel’s PCD is usually displayed after the number of studs, separated by a slash.  For instance, a PCD of 5/120 means that the wheel has five studs, and a pitch circle diameter of 120mm.  A PCD of 4/114.3 means the wheel is four stud with a pitch circle diameter of 114.3mm.

Measuring the PCD of a 5 stud wheel is a tricky business. It is much easier to determine the PCD by checking the manufacturers’ original specifications. When it comes to the PCD of a 4 stud wheel, one can roughly measure it, as the pitch circle diameter is the same as the distance between two opposite bolt centers.

Different cars have different PCDs, but often similar cars within the same manufacturers group have the same PCD.  Many of the VW Golf-sized cars in the VAG range have the same PCD and other wheel dimensions. Therefore, wheels are often interchangeable between these cars.