When installing a new set of tires, vehicle owners often end up overlooking the wheel offset setting, which worsens the stability and how the vehicle handles.
So, if you’ve noticed handling issues after changing wheels, you may be wondering – what is a wheel offset? Don’t worry, here is everything you need to understand about it!
What Is A Wheel Offset?
Wheel offset is the distance between the centerline of a wheel and its hub mounting surface. An offset of zero indicates an even alignment of the wheel with its mounting surface. Additionally, a negative offset makes the wheel push out of the vehicle while a positive offset makes it move inside.
If you want to learn more about how much wheel offset is good for your vehicle, what is a negative and positive wheel offset and more, keep on reading for more facts!
What Is A Positive Wheel Offset?
A positive wheel offset is when the wheel mounting hub is displaced from the center of the wheel and moved towards the inside of the car, which is represented by a positive value and measured in millimeters.
So, if you find out that a particular wheel has an offset of 25mm or +30, this indicates a positive wheel offset.
However, note that most front-wheel-drive and several modern rear-wheel-drive vehicles come with a positive wheel offset.
What Is A Negative Wheel Offset?
A negative wheel offset is simply the opposite of the positive offset described earlier, i.e. the wheel mounting hub is displaced towards the outside (or street-side) of the vehicle.
Negative offset values are always prefixed with a minus (-) sign, so an offset of -25mm or -30 indicates a negative wheel offset measured in millimeters.
For example, deep concave wheels, particularly those of off-road trucks, usually have a negative wheel offset.
Additionally, a negative offset pushes the wheels out of the vehicle’s fender, which gives it a more aggressive stance.
Is Positive Or Negative Offset Better?
With a negative offset, your vehicle will have a wider stance, which results in better stability and handling, which is particularly useful for off-road vehicles, as they will have a better grip when driving over rugged and uneven landscapes.
In contrast, positive offsets are generally safer and used more often than negative offsets.
Additionally, a positive offset allows you to install wider tires that will be tucked nicely inside the fender body and won’t cause any rubbing problems.
Does Wheel Offset Matter?
If you’re using the original tires that were initially installed in your car, you don’t need to worry about wheel offset at all.
However, if you are looking to upgrade or replace your wheels, you should definitely spend some time to make sure you select the appropriate wheel offset.
Selecting the right offset is essential, because if the offset is too negative, the wheels will rub against the fenders, and if the offset is too positive, the wheels might damage the inner suspension components.
Additionally, maintaining an appropriate offset will ensure that your vehicle delivers safety and stability while driving.
How Much Wheel Offset Is Ok?
It’s recommended to keep the wheel offset value within 5 mm of the old offset if you’re adding wheel spacers or reducing the width of the wheel by machining it, and the same rule applies if you’re installing new wheels that have the same width as your old ones.
However, if your new wheels are wider, you should adjust your offset accordingly to make sure your wheels don’t rub with the fender or the suspension components.
In this case, it is recommended that you have a professional mechanic install your new tires so that you drive with an appropriate wheel offset.
Does Wheel Offset Affect Alignment?
A negative or positive wheel offset does not affect the alignment of the tires since they are already aligned for a particular suspension design, wheel rim size, and offset.
However, if you are changing the wheel offset for any reason, you should have the alignment checked by a professional mechanic to avoid any issues in the future.
How Does Wheel Offset Affect Handling?
A wheel offset that is appropriate for your vehicle will only improve the handling performance, giving you more stability while steering and making sharp turns.
However, if you push the wheel offset value to an extreme in either direction, you will experience a steep reduction in stability and handling, especially in sharp turns and at high speeds.
As well, consistent rubbing of your wheels with the fender or suspension components will weaken your tires, increasing the possibility of accidents.
Ultimately, over time, the extra stress placed on your suspension components will also lead to further deterioration of your vehicle’s performance.
Does Wheel Offset Affect Bearings?
Increasing the value of an offset (whether in the positive or negative direction) will increase the imbalance of load experienced by the inner and outer bearings.
Overall, this might result in the bearings experiencing greater loads wearing out earlier than their expected life over time.
How Can You Find The Wheel Offset?
Manufacturers often imprint the recommended offsets directly on the wheels for ease of reference.
However, if there is no such imprint on your wheel, you can measure its offset manually by following these steps:
- Remove the rubber tire from your wheel to make the process easier
- Lay the wheel down on a flat surface and place a straight edge across its top surface
- Measure the distance from the flat surface to the straight edge, and subtract one inch from this reading to find the wheel width
- Divide the wheel width by two to find your wheel’s centerline measurement
- Next, find your ‘backspacing’ by positioning a scale on the top of the wheel mounting surface and measuring the distance between the hub and the wheel edge
- Finally, subtract the centerline from the backspacing value to get the wheel offset
Note that if your backspacing value is less than the centerline measurement, then you have a negative offset (and vice versa).
Can You Change Your Vehicle’s Wheel Offset?
You can change the offset of your wheels by replacing them with wider wheels, installing wheel spacers, or machining them down.
However, this is a tricky process in which you have to take care of factors such as current offset, required offset, wheel width, and backspacing clearance.
Therefore, it is recommended that you visit a professional mechanic if you are not very experienced when working with cars.
Do Wheel Spacers Change Wheel Offset?
Installing wheel spacers only reduces the wheel offset, pushing it in the negative direction.
For example, if your car has a 50mm offset, you can change it to 40mm by using a 10 mm spacer. However, keep in mind that wheel spacers cannot increase the wheel offset.
What Is The Difference Between Wheel Offset And Wheel Backspacing?
Although ‘wheel offset’ and ‘wheel backspacing’ are often used interchangeably, they do not refer to the same thing.
Rather, offset is the distance between the mounting surface of the hub and the centerline of the wheel, whereas backspacing is the distance between the hub mounting surface and the inner edge of the wheel.
Additionally, a wheel offset can be positive, negative, or neutral, while backspacing is mostly positive (except in some vehicles, i.e pickup trucks).
To learn more about wheels, you can also see our posts on what are staggered wheels, what are billet wheels, and what are forged wheels.
Conclusion
Wheel offset is the distance between the centerline of a wheel and the position of its hub mounting surface, with vehicles having a positive, negative, or neutral wheel offset.
Wheels move ‘inside’ in positive wheel offsets and move out towards the ‘street-side’ in negative wheel offsets. However, You only need to worry about wheel offsets when you are replacing your tires or installing wheel spacers.