When purchasing new wheels, there are things to consider. Design, diameter, width and colour are the main focus. Another important aspect often overlooked is offset.
Most leading wheel companies have already worked out wheel offsets to suit most vehicles with most rims, but what happens if you are ordering a rim that’s custom made for your ride? Will it fit? Will it be inside the guard? Will it fill the guards like you want it to? These questions and more will race through your head.
Wheel offset has a massive effect on these questions.
Wheel offset determines how far in or out the rim will sit in relations to the vehicle’s guard. This various with different widths of the rim on different cars.
Wheel offset works with the width of the wheel and is measured from the rims mounting surface to the rear of the rim. To make it easier to determine the wheel offset, convert the inch measurement to a millimetre measurement.
Here’s an example of how to measure wheel offset:
A wheel is 10 inch wide or 254mm, zero offset is the rim mounting surface being at four inches or 101.6mm but let’s round that off to 102mm for this example.
Now, if this 10 inch wide rim had a +20 offset, the rim mounting surface will sit at 122mm measuring from the rear of the rim. This would move the outside lip 20mm inwards if the original wheel width and offset was 10 inch wide zero offset
If the offset was -20, the measurement would change to 82mm, this would push the outside lip out 20mm if the original wheel width and offset was 10 inch wide zero offset.
The good thing about this day and age, is that everything can be found on the internet. There are websites that do all the calculations for you. Simply type in the size you have at the moment, E.G: 17×9 +30, then type the size you want to put on, E.G: 18×10.5 +25 and it works out how much inner and outer clearance you will have roughly.
The two main sites that prove to be most helpful are:
If you would prefer to see details and photos of what sizes and offsets other people have run on the same vehicles that you have, another good site is:
Hopefully this guide helps you when looking at purchasing new wheels.
For more information or pricing on any wheels listed on our site, contact our friendly sales team on 1800 099 634 or shoot us an email on firstname.lastname@example.org