If your rear wheels are wider and/or of a larger diameter than the front wheels, you have yourself a case of staggered fitment.
A staggered fitment is also referred to as a staggered application. Basically, it means that the wheels on the back of the vehicle are a different size than those on the front. Wider wheels are usually run on the back; for example, 19x8 on the front and 19x9.5 on the rear. This is typically done on rear wheel drive cars such as BMWs and many other RWD. Running wider wheels on the drive wheels means more grip on acceleration. A staggered fitment can also mean larger diameter wheels on rear, like 17" diameter on the front and 18" diameter on rear.
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