When you enter a shop to buy new wheels for your car, the first question the salesperson will ask is what the wheel offset is. It refers to the distance between the hub mounting surface and the centerline of the wheel. The offset is measured in millimeters. Here are a few things you should know about the offset.
Types of Offset
There are three types of offset, which include negative offset, positive offset, and zero offsets. Backspacing is an essential factor in offset. It refers to the space between the mounting surface of the wheel and the backside of the wheel. Now, let’s take a closer look at different types of offset in detail.
- Negative Offset– The wheel’s mounting surface is closer to the inner edge of the wheel. The wheel with negative offset offers less backspacing, and the wheel looks more dished out. This type of offset is popular in trucks and show cars.
- Positive Offset– In this offset design, the wheel’s mounting surface protrudes towards the street side. Most OEM car wheels have a positive offset. One advantage of positive offset is it offers maximum backspacing.
- Zero Offset– In a zero-offset wheel design, the wheel’s mounting surface is aligned with the centerline. The centerline refers to the centermost point of your wheel. If you have to cut the wheel half vertically, the knife will pass through the centerline.
How to Measure Offset?
The wheel offset is not mentioned on wheels. Even though some wheels have some specifications imprinted on the wheel, the information presented in digits is hard to decode. However, that should not be a reason to worry as you can always measure it manually.
Since it is difficult to measure the distance between mounting beads and the wheel’s centerline with the tire on, you can measure from the tire sidewall.
Do You Need to Change the Offset?
The decision to change the offset depends on your individual preference. Most people change wheel offset to give their car an aggressive look; for example, adding a 10mm wheel spacer would give your car a wider stance.
Which Offset Is Better for Your Car?
Most front-wheel-drive cars have a positive offset. If you want to install wider wheels than your OEM wheel, you have to reduce offset. When you reduce the offset, it brings the wheel towards the inner side.
If you put wider wheels without reducing the offset, the wheels will bump and scrap things you would not want. If you change the offset of a front-wheel-drive car, it will change the scrub radius. You will also experience differences in braking, acceleration, and steering.
Rear-drive vehicles have a negative offset. Changing the offset in a rear-drive vehicle will change the scrub radius and also affect steering. Unless you mess up with brake calipers while changing the offset, you will not notice any acceleration or braking change.
What Will Happen If You Choose the Wrong Offset for Your Vehicle?
If your backspacing or offset measurement is wrong while purchasing new wheels, you will have the risk of the wheel sitting too much inside the wheel well. It can lead to tire and wheel rub against the suspension.
Should You Go With a Different Offset in Winter?
If you have a positive offset, you can continue with the same offset while fitting winter tires. If you change to a lower offset, it will mean the wheels will stick out. It will spray salt, chemicals, and sand on your car as well as other cars passing by.
To sum up, the wheel offset determines how the wheel fits in your car. If you go wrong with your offset calculations, you run the risk of damaging your car suspensions or other parts that can lead to heavy repairs. If you are not sure about what offset is right for your car, you can always consult a professional who would give you the right advice.
