We're hoping there's some "there there" with this one, but here goes. Car & Driver went down to the GingerMan Raceway in South Haven, Michigan where they ran into some Ford engineers with a few pre-production 2011 Mustangs. Aside from some adjustable shocks (which C&D feels are most likely just for development), the big difference was the tires on one of the mules.
Pirelli P Zero Corsa R-compounds, to be precise, in place of the "regular" P Zeros found on 2010 Track Packers. In other words, pure supercar. In fact, those tires come stock on the Lambo LP560-4, for instance. The question then becomes, why would a Mustang need honest to goodness supercar meat? One explanation is that Ford is just playing around with different tire compounds. Another though, is much more interesting.
C&D claims that the Corsa R-compound car was lapping the 1.88 mile track just as quickly as the current BMW M3 they brought along. But how could a 315 hp car keep up on a track with a 414 hp car? Weight? Maybe, because the Mustang weighs about 200 pounds less than the M3. Don't say torque, because the Mustang only beats the M3 by 25 lb-ft there. Tires? Well maybe, but the Michelin Pilot Sport 2s on the Bimmer are pretty sticky in their own right. Despite all that, 414 horses should have cleaned up.
Well, what if the 2011 Mustang Mule with the fancy tires had a 5.0-liter, 32-valve DOHC Coyote engine kicking out 400+ hp and 400+ torques. The world's worst kept secret engine could also explain the similar lap times. Now dig this, there's also a small possibility that the white mule depicted in the article -- the one that appears to be missing a tailpipe -- isn't a V8 at all, but is instead an EcoBoosted V6 model. Did the car C&D ran into have the new 5.0-liter Ford V8 or the blown six? They didn't say. But if they saw the adjustable shocks that means they saw the hood up.