Tested: We Supercharged Our Ford Mustang Dark Horse

Edmunds

10-07-2025

The instruction manual is also very clear that the car can only take premium fuel. While that was the case before, it seems the consequences are much more dire. From the manual: "If fuel of less than 91 octane is present in the vehicle's fuel tank, the tank must be completely drained and refilled with 91 or higher octane to one-eighth of a tank. The fuel tank is returnless, therefore, initial fuel in the system will be low octane. Drain all fuel!" Quite the warning.
Hitting the test track
So was all of the time and money worth the effort? While we haven't had a chance to take it to another round of Edmunds U-Drags races quite yet, performance at our test track is promising. The newly supercharged Dark Horse hit 60 mph in 3.9 seconds, half a second quicker than before. It picked up even more speed down the straight, eclipsing the quarter-mile mark in 11.6 seconds at 125.6 mph. That's a full second quicker and more than 12 mph faster than before.
Getting a good launch in the Dark Horse took some patience and practice before, and the addition of an extra 310 hp hasn't helped the traction situation. While Dark Horses equipped with the six-speed manual come with launch control, our car is fitted with the 10-speed automatic and lacks any sort of launch control or race start feature. You simply have to roll onto the gas quickly but smoothly. Too much power and the rear tires will light up. Too little and the Dark Horse gets away too slowly.