Wheel Fitment Guide

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If you’ve got your eyes on a new set of wheels, the big question is always if they’ll fit. And not only that, but how well will they fit? The answer to this depends largely on the following:
  1. The total rolling diameter of your wheel and tyre
  2. Wheel width and offset
  3. The offset of the wheel
  4. Brake clearance
  5. Centre bore size
  6. Stud pattern
When choosing wheels, these factors need to be considered as a whole. With a little experience it’s easy to tell if certain wheels will fit your car without having to resort to a tape measure or making any calculations, but when clearances are reduced or you’re going for a tighter fitment you’ll need to take careful measurements and possibly test fit wheels before driving on them. As long as your car already has wheels which can be used for comparison (or you know the OEM specifications), it’s normally easy to determine if different wheels will physically fit.

      1. Lay the wheel face down (it makes no difference if a tyre is fitted or not)

      2. Put a flat edge across the wheel from one side to to the other and make a note of the measurement from the floor to the the flat edge. We will call this “Measurement A”.

      3. Next measure the distance from the back of the wheel to the flat edge and make a note of this. We will call this “Measurement B”.

      4. To calculate the offset, divide the value of “Measurement A” by 2 and subtract this from “Measurement B”. For clarification we can express offset as: (Measurement A/2) – Measurement B.

      5. The calculated offset may be a positive or a negative value.


When using spacers or adaptors, always use wheel bolts that are long enough while ensuring that nothing is fouled by bolts that are too long.


The centre bore of a wheel is the hole use to locate the wheel on the hub of the car. If the centre bores of your new wheels are smaller than your current wheels, the wheels can not fit as they will not be able to locate on the hub of the car. If the centre bore is larger on the new wheels, spigot rings should be used to effectively reduce the size of the bore. These rings are just inserts – usually made of plastic – that allow the wheel to locate in the correct way.


When replacing wheel bolts, you can generally get away with slightly different lengths but you can’t use bolts of a different diameter or thread pitch. As a rule of thumb, there needs to be at least seven full rotations for a nut/bolt to properly secure a wheel. Do not use grease of any kind on your wheel bolts as the manufacturer’s torque values are for dry assembly, unless stated otherwise.

All information on this page is credited to Wheel Shrine: http://wheelshrine.com/how-to/wheel-fitment-guide/