Wheels, Offset, and How to Calculate Fitment

When fitting aftermarket, or custom wheels, you should check for any clearance issues.

Incorrect fitment or Rubbing will wear out your tires, bearings, and cause other suspension components to fail or wear prematurely.

Offset is the measurement in millimeters from the wheel centre line to the wheel mounting face.
More often than not, offsets are positive(+) where wheel styles tend to be flush or convex.
Negative (-) offsets tend to have concave styling and the use of spacers. 

The Offset, or "ET" (Einpress Tiefe translates to Press Depth in German),
determines the distance between the center of the rim surface and
the face of the wheel where it is bolted to the hub.

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.

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".

WARNING: Incorrect offset can seriously affect vehicle performance.

Rim Measurement Diagram - Mini Mania Inc. Positive Offset Diagram - Mini Mania Inc. Negative Offset Diagram - Mini Mania Inc.
Rim Measurements Positive Offset Negative Offset

Example:

This stock 4.5" x 10" Mini Cooper S alloy wheel has a POSITIVE Offset of 35mm.
It would be seen as 4.5" x 10" wheel, 4 x 4" lug pattern, Offset of ET35.Offset explained - Mini Mania Inc.

This Minilite 6" x 10" Mini Cooper S wheel has a POSITIVE Offset of 15mm.
It would be seen as 6" x 10" wheel, 4 x 4" lug pattern, Offset of ET15.
Offset explained - Mini Mania Inc.

This Super Trax 7" x 13" Mini Cooper S wheel has a POSITIVE Offset of 7mm.
It would be seen as 7" x 13" wheel, 4 x 4" lug pattern, Offset of ET07.
Offset explained - Mini Mania Inc.

This Alleycat 7" x 13" Mini Cooper S wheel has a NEGATIVE Offset of 7mm.
It would be seen as 7" x 13" wheel, 4 x 4" lug pattern, Offset of ET-7.
Offset explained - Mini Mania Inc.

 

a wheel with NEGATIVE (-) 15mm OFFSET or ET would be shown as ET-15
a wheel with POSITVE (+) 7mm OFFSET or ET would be shown as ET07



 

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