Identifying the wheel size
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Markings on the inner side of the wheels identify 18-inch Turbo wheels with the sizes 9J x 18 RO 52 and 10J x 18 RO65.
The sizes together with the rim offset (RO) and spare part number are marked with A or B. The correct version for the model is marked with an X which is struck into the "A" or "B" boxes provided.
Fig 1 shows model "B".
Marking "A"
18-inch Turbo wheel: 10 J x 18 - RO 65 Spare Part No. 993 362 140 01.
Marking "B"
18-inch Turbo wheel: 9 J x 18 - RO 52 Spare Part No. 993 362 138 00.