2011 Ford Mustang GT 5.0: Dyno Tested

Oh boy. Friends, what we have here in the 2011 Ford Mustang GT 5.0 is something that's sure to add a big ol' shovelful of coal under the pressure cooker that is the Camaro/Mustang rivalry.

You see, the Mustang GT's newfangled all-aluminum DOHC 5.0-liter V8...it makes some power. A lot of power, actually.

Ford claims it churns out 412 horsepower and 390 pound-feet of torque. While these numbers by themselves don't better those of the Camaro SS, on paper the Mustang's leaner curb weight might be able to put them to better use. Wait a week and we'll tell you all about our driving impressions of the 2011 Mustang.

In the meantime, while other outlets busied themselves doing burnouts, we were putting Ford's claims of power and torque to the test. Yes, for you, the loyal reader, we dyno-tested the 2011 Mustang GT.

What the Mustang's 5.0-liter V8 lacks in displacement relative to its crosstown rival, it makes up for in its more capable valvetrain. Overhead cams are nothing new to Mustangs. Independent phasing of the intake and exhaust cams is. This capability allows the engine to breathe better over more of its rev range while improving fuel economy and reducing emissions.

We were only interested in the power part of the new five-oh, though. And here's what the Dynojet divulged:

It took several pulls on the dyno to achieve a stabilized result. Each run eked out more power as the ECU probed the limits of the 91-octane fuel. The Mustang finally produced stable and repeatable numbers upon the 7th dyno pull.

With 250 lb-ft on tap at 2,000 rpm, torque starts out pretty strong. It then builds linearly and remains above 350 lb-ft from 4,150 to 5,500 rpm before tapering gently to the 6,850-rpm fuel cut.

Peak numbers are 365 lb-ft of torque at 4,350 rpm and 395 hp at 6,600 rpm. All of these at-the-wheels figures were obtained in 4th gear on a Dynojet 248 chassis dyno and include a 3% SAE weather correction factor.

Driveline loss for a solid axle-equipped car like the Mustang is typically 11-13%. This is a bit less than the usual 15-18% you'd expect on an IRS car, as solid axles have fewer power-sapping U-joints in their driveline. Hence, we should expect to see about 358-367 rwhp from this car.

Clearly, the 395 rwhp figure we measured is of particular interest since it implies one of two things -- either Ford is being conservative with its 412-hp flywheel rating, or the preproduction example we tested is unusually healthy. We're leaning toward the former, but we won't know for sure until we test a production 2011 Mustang.

One thing's for certain -- the reprise of the Mustang 5.0 is shaping up to be a strong pony.