If you're tired of hearing, "Those wheels won't fit on your truck," or if you're considering a billet wheel that can be custom-built to fit your special lug-tucking needs, then this tech is for you. We put together a how-to guide that will help you use the simplest of tools to measure your own backspacing and wheel offsets, and how to use those measurements to find a wheel that will tuck deeply into your fenderwell.
Using the backspacing measurement, you can order wheels from your local wheel store without paying attention to the salesperson ranting and raving that there is "no way in hell you're going to fit a 22-inch wheel on that S-10." We decided to see if we'd be able to fit a set of Boyd Coddington 19x8-inch wheels on a '93 Toyota and take the guesswork out of wheel purchasing. Boyd Coddington Wheels offers a service that allows you to test-fit wheels so you can get the exact backspacing you need. Not every wheel manufacturer offers this service, so we'll shed some light on finding the optimum backspacing for your mini.
Offset Equation Using a 10-inch-wide Niche Over Ride wheel as an example, we can easily find the offset using the backspace measurement. Measurements needed: Wheel centerline (wheel width divided by two) and backspacing Equation: Backspacing minus wheel centerline equals offset Note: If the answer is negative, then you have a negative offset; if it's positive, you have a positive offset. A 10-inch-wide Niche Over Ride has a wheel centerline of 5 inches and the backspace is 6-1/2 inches Offset: 6-1/2 (backspace) minus 5 (wheel centerline) equals 1-1/2 inches (positive offset)
Most wheel companies have offset charts by wheel width, so the main measurement you need is the backspacing. To find the backspacing, you'll need a straightedge, a tape measure, and a weighted bob.