What is the Difference Between 9x4-1/2 and 9x5-1/2 Wheels

Published 11/11/2014

Question:

What is the difference between 9x 41-2 and 9 x 5/1-2. Rims

asked by: DJ

Expert Reply:

First off, the 9 must represent the wheel diameter, which is an odd size. So if 9 is the diameter that would make 4-1/2 and 5-1/2 the width.

The diameter is not the actual overall diameter of the wheel, it is the diameter of where the tire sits on the wheel. And the width is not the overall width, it is the interior width where the tire sits, from bead seat to bead seat. I have linked a video to the right as an example. In it our tire and wheel expert explains the measurements.

I can't imagine that the 9x4-1/2 or 5-1/2 would be the bolt pattern. The most lugs I have seen on a trailer is 8. Some vehicles have 10, some even more.

expert reply by: Michael H