What is offset? In short, it’s a way of measuring how your wheel is going to sit in relation to the body of your vehicle. More specifically, it describes the relationship between the mounting surface (sometimes called the bolting face) of your wheel, and the centreline of your wheel.
Calculating offset
The centreline of your wheel is easy to understand - it’s the line down the middle of the wheel. This isn’t the line that runs from face to face, but in the middle of the circumference of your wheel.
There are three types of offset, each of which describes the relationship between the mounting surface and the centreline:
- Zero offset, where the mounting surface and centreline are completely in line
- Negative offset, where the mounting surface is behind the centreline
- Positive offset, where the mounting surface is in front of the centreline
You calculate the offset by simply determining how many millimetres of difference there is between the centreline and the mounting surface. So if the mounting surface is 20 mm behind the centreline, you have a -20 mm offset. If it’s 20 mm in front of the centreline, you have a +20 mm offset.
How offset affects your wheels
Offset works in a bit of a strange way.
Negative offset makes your wheels protrude outwards in relation to the body of your vehicle - in other words, more of the wheel will be visible when viewed from the street.
Positive offset does the opposite - your wheels will end up closer to the body of your vehicle, and be less visible from the street.
For this reason, negative offset is usually preferred, especially on after-market truck wheels. Not too many drivers are looking to hide their new wheels.
Intentional and unintentional offset
Intentional offset is commonly used to modify the look of your vehicle. You want to be careful, however - some of the shadier folks selling wheels on the market don’t know how to do the job right.
In those scenarios, you can get an unintentional offset, where the wheel ends up with too much positive or negative offset. That can lead to all kinds of problems, including:
- Poor handling
- Damage to brake parts
- Vehicle instability
- Increased steering wheel kick-back
That’s one of the reasons it’s important to always choose a trusted partner for aftermarket wheels.
Our specialty is custom wheels and rims in Edmonton. We’ll get you a new set of wheels with perfect offset. That includes negative offset wheels that won’t compromise your safety, nor your driving experience.