Will those sexy new rims fit your vehicle?
You’ve spent hours drooling over thousands of gorgeous images of sexy new rims and you’ve finally seen the style and design that you want. You have to have them, nothing else will do… but there’s one thing that could ruin everything; will they fit on your vehicle?
For those sexy new rims to fit correctly they have to match the pattern of your vehicle’s lug nut studs and clear the inside wall of the wheel wells. To tell if they will or won’t fit you’ll first need to read the wheel’s specs.
Generally a wheel’s specifications will be listed in this format: 15x8, 5x4.05 OS: -12mm BS 4.03”
Understanding these numbers is easy and will allow you to determine if a particular wheel will fit on your vehicle.
Typical bolt patterns
The first set of numbers (15x8) is the wheel’s physical size in inches, listed diameter first and depth last. So in this case the wheel is 15 inches in diameter and 8 inches deep, front to back.
The third figure (OS: -12mm) refers to the wheel’s offset. The offset is the distance from the wheel’s hub mounting point to the wheel’s centerline, which will be either a positive offset, negative offset, or zero offset.
A positive figure indicates a positive offset and the hub mount will be closer to the outside edge (the road side) of the wheel, giving a flatter profile when viewed from the outside.
An alloy wheel’s specs explained
The figure 0 indicates a zero offset wheel. The hub mount that is in line with the wheel’s centerline and has a traditional or ‘neutral’ appearance when fitted to a vehicle.
The fourth and final figure (BS 4.09”) is the backspace, which is the distance from the hub mounting surface to the inside or inboard edge of the wheel. It can be given in either inches or millimeters.
From these simple figures you can determine whether those new rims you’re lusting after will fit your vehicle or not.
Positive, zero and negative wheel offsets
The bolt pattern is often the stumbling block when buying new rims. A 4-stud hub is never going to work with a 5-hole wheel, and if the diameter and spacing of the studs don’t correctly line up it won’t fit either. However, a bolt pattern adapter can adapt a vehicle’s existing hub arrangement to accept the shiny new rims you’ve set your heart on.
Lastly, double check that your dream wheels will fit over your vehicle’s axles. Most aftermarket wheel manufacturers make the central hole sufficiently wide in the knowledge that their wheels will be fitted to a variety of trucks, 4x4s and cars, but it doesn’t hurt to check before you buy. Once again, if it looks like there might be a size issue, spacers and adapters can usually be employed to sort things out.
By John Bone