Dimension designation for wheel rim

Wheel and rim dimensions are designated in accordance with the examples in the table below.

The car has an approval for the complete vehicle with certain combinations of wheel rims and tyres.

All wheel rims have a dimension designation, for example: 8Jx18x42.5.

8

Rim width in inches
JRim flange profile
18Rim diameter in inches

42.5

Off-set in mm (distance from wheel centre to wheel contact surface against the hub)