The “muscle car look” dates back to the original muscle-car era of the late 1960s and early 1970s. These were the times where the larger displacement your motor, the better off you were. Hence big names like the 428 Cobra Jet, Boss 429, Boss 351 and many more. However, the Mustang has always pretty much operated on the fact that light, nimbleness always trumps raw power. A great example of this was that if you were to line up a Boss 302 and a Boss 429, you’d be surprised at how well the 302 does with a stronger power-to-weight ratio. With this ideology, that’s why the Mustang is still considered the quintessential pony car even by today’s standards.
"as much rubber as possible to the asphalt"
What does that mean for wheel fitment? Well, staggered wheels are typically what is found on these muscle cars. When it comes to huge power numbers, traction will become an issue, so the solution was to outfit the rear with larger width wheels and tires for more grip. On the other hand, square fitment is not only seen on regular economy cars, but also track cars as well. For vehicles that are meant to regularly carve the hard corners of a road course, you’re going to want as much rubber as possible to the asphalt. This is achieved usually by an 18” x 10” wheel at each corner depending on brake clearance.
Mustang Staggered Wheel Fitment
Dating back to the 1960s, staggered wheels are truly a classic, iconic look for any body style of the Ford Mustang. The term staggered wheels directly means that the wheels in the front and rear are different sizes. On muscle cars with rear-wheel drive, a staggered setup usually refers to wider wheels in the back in order to fit larger tires for more traction.
The love behind staggered wheels is directly correlated with muscle cars in the drag racing scene with “bigs” and “littles”, or slicks on the rear and smaller front runners up front.
Staggered wheels are still seen on many performance cars today, like the Mustang GT with the Performance Package with 19” x 9” wheels in the front and 19” x 9.5” wheels in the rear. They’re even more exaggerated on the 526 horsepower GT350R with 19” x 11” wheels in the front and 19” x 11.5” with meaty 315mm wide tires in the rear!
However, keep in mind that staggered wheels also have a couple of downsides. First off, wider tires are typically more expensive since they’re for performance-oriented vehicles. A staggered setup also means that you won’t be able to rotate your tires from front to rear, and with some performance tires that are directional, you may not even be able to rotate them from side to side leading to reduced overall tire life.
Mustang Square Wheel Fitment
Aside from regular cars off the showroom floor, you’ll see a square wheel fitment on most road course and track cars. The term square wheel fitment refers to the fact that all four wheels are the same size all around the vehicle.
You’ll see this on most vehicles off the dealer lot for various reasons. First and foremost is cost. It’s going to be cheaper to produce four wheels of the same size for a line of vehicles rather than two different sizes for the front and rear. Simplicity and practicality also plays a role in this because tire rotations are easy and straight-forward along with tire selection.
When it comes to high-performance track-based vehicles, you’ll also see square fitment in most cases. A great example of this is the 2012-2013 Boss 302S featuring 18” x 9.5” BBS wheels on all four corners. An 18” wheel allows for a lightweight design, something that is essential in racing, especially if it’s unsprung weight. On top of that, the wide diameter of 9.5” on all four corners allows for 275mm of tire contact at each corner. That means there is roughly 43.3” or over 3.5 feet of tire contact for the whole vehicle. That’s quite a bit of rubber which means sheer, balanced grip, everywhere.