01772 299825
WHEEL OFFSETS EXPLAINED - RIM WIDTHS ET - Q&A'S - START HERE
Will My Wheels Fit
1 - Firstly you need to know what size and offset you cars wheels are?
2 - Choose a new wheel design (unless if your extending your wheels with spacers)
3 - Drop a straight line ( plumb line ) from the top of your wheel arch.
4 - Measure the gap between the line and the wheel rim edge ( NOT TYRE )
If you have a 10mm gap, you can fit 10mm spacers providing the tyre does not over hang your wheel.
Another example.
You wheel is 17 x 7 ET45 and you have a 10mm gap , you can now fit 17 x 7 ET35 wheels or
17 x 8 ET 32
What is wheel Offset? - Lets explain
Offset is the distance between the mounting surface of the back of the wheel and the wheels true centre line and it’s important for two reasons. First, if the offset of your aftermarket wheels varies too much from the manufactures standard specification it can compromise steering response and directional stability as well as putting excess load on components like wheel bearings. Secondly the wrong offset can make the wheels or tyres may foul suspension, brake components or the inner arches.
What do wheel offset numbers mean?
Offset is expressed as an ET number, (ie is ET38) and the ‘ET’ is a shortened version of the German word ‘Einpresstiefe’ which means ‘insertion depth.’ The number is the distance in millimetres between the centre line and the mounting surface.
It sounds confusing but the important thing to remember is wheels with a higher offset will sit UNDER the wheel arch more than a lower offset which will POKE OUT towards the wheel are more.
Study the image above, same wheel width,same tyre size, different offset, notice the colour green and yellow.
Positive Offset
A positive offset occurs when the hub mounting surface is on the street side (the side you see) of the center line of the rim. Most factory rims will have this type of offset.
Zero Offset
When the hub mounting surface is centered within the rim, it is known as a zero offset.
Negative Offset
If the hub mounting surface is on the brake side of the center line of the rim, it is considered a negative offset or “deep dish”.
