ALLOY WHEEL OFFSET
An alloy wheel offset is the distance in milimitres between the mounting face at the back of the rim and its centre line. This is expressed as an ET number which comes from the German term 'Einpresstiefe' meaning 'insertion Depth'.
Getting the correct offset is crucial not just for the looks but to stop the wheels or tyres scrubbing the inner arches or suspension components.
There are three types of wheel offset.
In simplier words, if the center is closer to the front of the wheel, it has "positive" offset.Majority of aftermarket wheels have positive offset.But this does not mean that all aftermarket wheels with positive offset will fit your car.
Every car make has unique wheel specifications and this includes the offset value.Just like bolt pattern (or stud pattern) the offset has to match the factory settings for a proper fitment.
The good news is offset value is not as strict as bolt pattern.It has a tolerance range.So when you are buying a new set of alloy wheels, you can be a bit flexible on offset values.
The tip is ;you can go 5 mm-7mm off the original offset value.
Let's give an example:
Assume that you have a Fiat Punto year 2007 and you are looking for new aftermarket alloy wheels for your car.If you check the manual of your car, you will see the Fiat Punto requires wheels with the following specs:
Rim size:15 inch alloy wheels (as standart)
As you can see, your original offset value is 43.This means you can fit a 15 inch alloy wheel on your car (with 4x100 bolt pattern obviously) which has an offset between 35 and 43.The closer to the original value, the better it is. We generally supply 38 offset which is generally OK for most car makes.
An important note for Peugeot and Citroen Owners:
In some cases, you can fit wheels that come off from a different car make. A few examples; Wheels from Audi A3 (year 2006) will fit Skoda Octavia (year 2005) or wheels from Nissan Note (year 2007) will fit Honda Civic (year 2005).They have the same bolt pattern and similar offsets.
However this will not the case for Peugeot and Citroen owners.We have received lots of e-mails about this so we want to clearify this for you.Unlike other car makes, Peugeot and Citroen require lower wheel offset values.This is generally between 15 and 20.
The biggest mistake that people make is that they think that all 4x108 patterned wheels will fit their Peugeots or Citroens. They do not realise that the wheels they are struggling with is wrong offset (35 let's say) for their cars.You cannot fit a big offset wheel on a Peugeot or a Citroen unless you are using wheel spacers to reduce the offset size.
Tyres will be too close to the suspension system and they will eventually start to scrub on the suspension components which is obviosly not good.
So be careful when you are looking for cheap second hand wheels on the web.Make sure about the offset of the wheels you are buying.