Upgrading your factory wheels for competition or street performance can have several advantages in addition to stylish looks. To help you choose what type of wheels you need and how to properly measure for them, we sat down with the team at Bowling Green, Kentucky-based RC Components.

Competition Wheels vs Street Wheels: What’s the Difference

Competition wheels are generally lightweight and are built to be stronger for high-performance applications. Vehicles that make a lot of power and are used at the drag strip can use an optional beadlock ring that secures the tire to the wheel and prevents slippage under hard acceleration. “Our Comp Series wheels are mainly designed for race applications, but as you more than likely have already seen… we have hundreds of drag and drive competitors using the Comp series wheels with zero issues,” says Tony Bumpus, Sales and Marketing Manager at RC Components.

Ford Muscle’s Project Magneto uses a set of RC Components’ single beadlock 17×11 Exile rear wheels and 18×4 Exile front wheels. This wheel setup allows the Mustang to perform well at the track without sacrificing too much street drivability. “You can swap these wheels on, put the party pulley and tune in at the track, but back it down for the street – with stock brakes that work fantastically in traffic and stoplight to stoplight,” says car owner Scott Parker.

Competition wheels for drag racing may need to be SFI 15.1 rear wheel and SFI 15.2 front wheel certified for safety purposes, depending on your sanctioning body and class. The standard dictates material strength and composition.

Street performance wheels are intended for style, plus they generally shave a few pounds over factory wheels for improved unsprung weight. They typically won’t use a beadlock ring and are mounted to the rim with air pressure alone. “The Streetfighter wheel series carries the exact same SFI rating as the Comp Series, but allows for more brake clearance and is a thicker design. The thicker design will add about four to five pounds per wheel, but the wheels are still quite a bit lighter than the factory setups and have the strength to handle the power a lot of these late model cars are making,” Bumpus explains.

For Project Magneto, installing RC Component wheels provided a perfect balance between strip and street use.

“When we added a supercharger, we needed stickier tires, so we to a Mickey Thompson ET Street R drag radial. Not only were these tires stickier, but they were larger. And with the radial prep that we get out here on the East Coast, these things can really hook. So, we needed both a wider wheel in the rear and something with a single beadlock to hold the tire to the wheel and keep it from spinning. Additionally, because I drive this car on the street, I didn’t want drag brakes on the rear. The really cool thing about the RC Component wheels is that by running a 17-inch wheel, I still get very good tire selection with a beadlock but without all the crazy non-street-friendly mods needed to run 15-inch wheels on an S550 Mustang,” Parker explains.

Common Wheel Fitment Mistakes and How To Avoid Them

Wheels are an investment. Like any investment, planning and preparation go a long way towards a successful outcome. Here are some common mistakes to learn from and how to properly measure for a set of performance wheels.

Mistake 1 – Not considering brake caliper clearance. “Brake to wheel fitment is very critical,” Bumpus says. “Each car will have different-sized brakes/rotors depending on year and model.” This is especially important if you have larger factory or aftermarket performance rotors and calipers. You’ll also want to take into consideration room for air passage cooling. Several measurements should be taken, including from the center of the wheel hub to the top of the caliper and the wheel mounting surface pad height. Bumpus recommends measuring from the centerline of your hub to the very tip of your caliper or whatever is the highest point before the wheel touches.

Mistake 2 – Measuring the bolt pattern incorrectly. Wheel studs are configured in a variety of bolt circle patterns. Identifying how many studs and proper measuring is key. For even bolt patterns such as four, six, and eight wheel studs, measure the middle two studs directly across from each other, center-to-center. For five stud patterns, commonly found on most late-model domestic vehicles, measure from the top of one stud to the center of the third stud.

Mistake 3 – Neglecting to consider suspension travel. If the wheel is too large, it may rub against the inner fender while traveling down the road. To determine suspension travel,l you can reference factory or aftermarket specs for shock travel. Another method is to lift the car until the wheel is off the ground. Then measure from a fixed point on the chassis to the center of the wheel hub as shown here. Lower the car to ride height and measure again. Then compress the suspension fully by using a jack under the control arm and measure again.

Mistake 4 – Not fully considering backspacing effects. Backspacing is the distance between the back of the wheel flange and the mounting hub face. Backspacing directly affects inner clearance to the suspension and outer clearance to the fender. To get a proper measurement, lay the wheel on a flat surface with the back side facing up. Then place a straight edge across the wheel flange and measure down to the mounting hub face.

Mistake 5 – Not considering available tire choices. Research your tire options in advance and take sidewall height into account when determining available wheel well space. Keep in mind that tire diameter slightly increases as they get hot, and they deflect under high-torque launches. Give yourself a little extra space to avoid any issues.

An Example Of How To Figure Out The Right Set Of Wheels

Let’s look at an example of how you would approach getting the right set of wheels for a modern muscle car. The seventh-generation Mustang is perfect since these cars have a lot of different options that will impact what wheels you can use.

The 2024-2025 S650 seventh-generation Mustangs feature different brake packages depending on the model. Mustang GT Performance Pack models come equipped with four-piston Brembo fixed calipers up front, with single-piston floating calipers in the rear. The more track-oriented Mustang Dark Horse benefits from larger front 6-piston fixed Brembo calipers and four-piston Brembo calipers rear. In addition, Dark Horse models come equipped with track-ready rear suspension featuring MagneRide adaptive dampers and performance rear knuckles. When it comes to wheel options, the brake and suspension upgrades add up to less available space.

“The main concern with S650 Mustangs is brake clearance and the width of the rear wheels. Everybody wants the widest wheel made, and that does not work for these cars. The reason the 17x11s will not fit is because the tire will hit the inner suspension or outer wheel well, depending on the backspace you choose. We have a direct fitment for these cars in a 17×10 that fits perfectly,” Bumpus explains.

With thoughtful consideration and careful measuring, you can get the right set of performance wheels for your vehicle. The type of wheels you select will depend on how you plan to use the vehicle. As long as you make sure the wheels will clear brakes, suspension, and fender wells, you can successfully upgrade your wheels right the first time.