Between 1988 and 1993, Saab used the 4 by 108 bolt pattern. This pattern is irregular and was only used by a handful of vehicle manufacturers in recent history, including Alfa Romeo, Audi, Ford, Mercury, Oldsmobile, Peugeot, Porsche and Volvo .
Wheel stud patterns can be broken down into number of lugs by the diameter of the circle formed by the lugs. As of 2014, four-lug patterns are only used on subcompact and compact cars and the 4 by 100 pattern is far more common. Five-lug patterns allow for more weight to be supported by each wheel and are influencing the phase-out of four-lug wheels.