How to Get Perfect Rear Wheel and Tire Fitment

Rubber Rendezvous
Stuffing the Biggest tires you can.
If there is one thing that can make or break the appearance of a car, it’s the wheels and tires. Not only is a car’s appearance “made” with the right choice of wheels and tires, but its ability to win races hangs within the balance if chosen incorrectly.Fitting the largest tire possible under the rear of your car doesn’t take an Algebraic degree. There are a lot of variables involved when it comes to measuring for a larger tire (brakes, suspension, and the exhaust), can be an interference.

Fitting the largest tire possible under the rear of your car doesn’t take an Algebraic degree, but there are a lot of variables involved when it comes to measuring for a larger tire (brakes, suspension, exhaust) and can be an interference.

So how do you measure to see what size wheel and tire will actually fit under your car? There are a few measurements that you will need to know, in order to get a wheel that will fit. You’ll need to know how much backspace will fit, the overall wheel width you have room for, and what diameter wheel and bolt pattern you need. There

There are a couple of ways to measure for wheel fitment. First, you can use a tape measure and a straight edge. To measure the backspace, take a straight edge that is at least as large as the wheel/tire diameter that you plan to use, and place it against the brake drum (or rotor face if using disc brakes). Now you can take a measuring device (tape measure or ruler), and measure the distance from the straight edge to the inner fender of the car. Then, take your measuring device, and measure how much room you actually have (inner fender to wheel well lip on outside quarter panel.) Remember, when measuring for the total width, the tire you mount on your wheel will have a slight bulge to it, so take that into account. Typically, if you leave 1 – 1-1/4 inches of space, you should be fine.

When you are done measuring, you need to decide what tire will fit your wheel—and wheel well opening. Tires have a couple of measurements you need to know—section width, tread width, sidewall height, and overall diameter. Section width is the distance from sidewall to sidewall at its widest point (measured after the tire is mounted and inflated.) This is the measurement that gives cause for the 1 – 1 ¼ inch spacing between the rim edges and the vehicle. Tread width is self-explanatory; it’s the width of the tread pattern. Sidewall height is the distance from the rim to the tread, and overall diameter is, well, the diameter of the tire after it is mounted.You’re probably thinking that this seems like a lot of work, and although it really isn’t that hard, if you want to make it so easy that—well, even we can do it, you need to check out the Wheel Rite tool from Percy’s high performance. The Wheel Rite tool is lightweight, easy to assemble, and it works on 4- and 5-lug hubs. This tool allows you to get a perfect fit the first time when selecting new wheels and tires. Percy’s tool bolts onto your vehicle’s hub to simulate wheel diameter, wheel width, backspacing, and tire profile. The Wheel Rite allows you to simulate a number of different sized wheels and tires without the expense or hassle of having multiple sizes of wheels and tires on hand.

You’re probably thinking that this seems like a lot of work, and although it really isn’t that hard, if you want to make it so easy that well, even we can do it, you need to check out the WheelRite tool from Percy’s High Performance. The WheelRite tool is lightweight, easy to assemble, and it works on 4- and 5-lug hubs. This tool allows you to get a perfect fit the first time when selecting new wheels and tires. Percy’s tool bolts onto your vehicle’s hub to simulate wheel diameter, wheel width, backspacing, and tire profile. The WheelRite allows you to simulate a number of different size wheels and tires without the expense or hassle of having multiple sizes of wheels and tires on hand.

Overall, we feel that the tool could be a little sturdier, but it worked for us. It’s not a tool designed for commercial use, but for the enthusiast, it can save you a bunch of money by helping make sure you choose the right size wheel and tire package the first time.

When measuring to fit the largest wheel possible under the rear of your car, backspace is a huge factor. To find out how much room you have, measure from the wheel face of the hub (where the wheel rides), to the closest point on the inner fender. Take a straight edge and hold it on the hub face, and then measure back.

What the previous measurement gets you is the same as if you actually have the wheel that you are measuring.
To measure for total wheel width, take your straight edge on the wheel hub (vertically), and then measure from the wheel well lip, to the inner fender. If you use a measuring stick, you can also get a backspace measurement.

What the previous measurement gets you is the same as if you actually have the wheel that you are measuring.

If you want to make measuring for wheel and tires easy, then you need the Percy’s Wheel Rite tool.

The wheel Rite tool bolts directly to almost any 5 lug wheel pattern.

By setting up the WheelRite tool with whatever dimensions will fit your application, you can even find out what tire will fit by bending and installing the wire to fit any tire profile. We were limited to a Mickey Thompson 28 x 10.50-15 tire.

By rotating the axle, the WheelRite can show any clearance issues that you might encounter, and allow you to either fix the issue or adjust your final tire/wheel size. Either way, this tool eliminates the need to hope they fit but have to try again when fitting wheels and tires.

The WheelRite tool allowed us to figure out what backspacing we needed, and what tire diameter would fit our car. Using our Holeshot wheels with a rim size of 15 x 8 inches, having a backspace of 5-7/8 inches.