Three numbers decide whether a wheel works in your car: the diameter, the dish, and the bolt pattern. The bolt pattern is the easy one, because almost everything here shares it.
The bit that makes this simple: 6 x 70 mm PCDMOMO, OMP and Sparco all drill their wheels on a six bolt, 70 mm pattern, and so do the boss kits and quick releases that suit them. That means a MOMO wheel goes on an OMP boss, and a Sparco wheel goes on a MOMO boss. You are choosing on size and feel, not on compatibility.
Diameter
Every rim below is drawn at true relative size. Forty millimetres looks like nothing written down and is very obvious once you are sat behind it.
Smaller means quicker and heavier. You turn less to get the same lock, and you work harder to do it, because you have less leverage at the rim. On a car without power steering that trade bites hard at parking speed and barely at all once you are moving.
350 mm is the most common size on the site by a distance, and it is the closest to what most cars left the factory with. If you are replacing a standard wheel and you are not chasing a specific change, that is the safe starting point.
Dish
Dish is how far the rim sits toward you from the mounting face. It is the number people forget, and it is the one that decides whether you can still get in and out of the car.
Adding a quick release? Go flatterA boss kit and a quick release together add a real stack of depth between the column and the rim, and it all comes toward you. If you are fitting both, a flat or shallow dish wheel usually ends up in the right place. A deep dish on top of a quick release can put the rim in your chest, especially in a fixed back seat.
The exact dish figure in millimetres is listed on every product page under Wheel Dish Size, so you can compare like for like rather than going on the type name alone.
Spokes and grip
Grip material is mostly preference, with one practical point: suede and alcantara give the best feel in gloves and the worst life in a road car that lives outside. Leather is the sensible all-rounder. Wood and polyurethane are for classics, where the look is the point.
What else you need
A boss kit, always
An aftermarket wheel does not bolt to your column. A vehicle-specific boss kit adapts your column spline to the 6 x 70 mm pattern, and there is one for almost every car. Ours are listed by vehicle, so search your car and year.
A quick release, if you want one
The quick release sandwiches between the boss and the wheel, so you still need the boss. It makes getting in and out of a caged car far easier and it is worth having if you are climbing over a door bar. Remember the depth it adds when you pick the dish.
Horn and buttons
Some wheels come with a horn push and some do not, and it is listed on every product. If your car needs an MOT, check before you order rather than after.
Tell us the car and what you are trying to changeWhether you want it quicker, closer, further away or just tidier, plus whether a quick release is going on. Diameter and dish work together and it is easier to get both right in one go. Call 0115 989 3488 or email Sales@GSMPerformance.co.uk.
Diameters, dish types, spoke counts and materials are read from our own product data, checked 2 August 2026. The 6 x 70 mm PCD applies to the MOMO, OMP and Sparco wheels and boss kits we stock; the Reverie carbon wheels and some classic patterns differ, so check the product page.
