Ford Is Cooking Up a Super-Mustang: GT500 Successor With New Engine and Wild Design Spotted Testing

A major shake-up is coming to the Ford Mustang lineup. The company is working on a successor to the GT500—and judging by what’s already been spotted, this one’s going to be something special. Even under heavy camouflage, the test mules seen around Detroit reveal some intriguing details. One standout: the exhaust outlets are now rectangular and mounted vertically. It not only gives the car a more aggressive stance, but also improves cooling by creating more space for hot air to escape.

Up front, the new Mustang sports oversized air intakes that dwarf those on the Dark Horse. That means more airflow to the radiator—and possibly the intercooler—helping the car keep its temperatures under control during hard driving. Unlike previous versions, the outer vents aren’t fake trim pieces; they’re fully functional openings.

Interestingly, two distinct prototypes were seen during testing. One ran on Michelin Pilot Sport 4S tires, the other on track-focused Cup 2s. The tire sizes are serious: 305/30ZR20 up front and 315/30ZR20 out back. That’s an inch wider than what the Dark Horse wears and significantly broader than the standard models. Wider rubber should translate into better grip and more stability at high speeds.

Through the 20-inch wheels, you can spot noticeably larger brake rotors—clear evidence Ford is engineering this setup for extreme use. The body appears wider as well, likely to accommodate a broader track and improve overall stability.

One small but telling detail: a massive rear wing was spotted inside the cabin, unmounted, suggesting engineers are still experimenting with placement to dial in maximum downforce.

As for the engine, rumors point to an updated version of the 5.2-liter supercharged Predator V8—the one that made 760 hp in the GT500 and has already been pushed to 815 hp in the GTD. Some believe Ford is preparing an even hotter variant, possibly under a new name such as “Legend.” Others speculate about a new 7-liter V8 inspired by the historic 428, which would be a dream come true for muscle-car purists.

For now, we wait for Ford to make it official. But one thing’s clear: the next Mustang is shaping up to be the most powerful and advanced in the car’s history—while still carrying the unmistakable spirit of the legend.