The much-anticipated 2012 Chevrolet Camaro ZL1 debuted at the Chicago Auto Show earlier this year, putting Ford'* Shelby GT500 squarely in its sites. While official horsepower numbers weren't released at the time, Chevrolet did state that the supercharged 6.2-litre V8 would "produce an estimated 550 horsepower and 550 pound-feet of torque," putting it on par with the Shelby.

Now, a new report states that the official horsepower rating of the ZL1 could be "north of 570 horsepower," placing it in between the Cadillac CTS-V (556 hp) and the Corvette ZR1 (638 hp). While this will surely give the flagship Camaro a slight edge compared with the current GT500, Ford isn't quite ready to hand over the muscle car crown quite yet, though. A 620-hp version of the GT500 is rumoured to be in the works for 2013 or 2014 with suspension tuning done on the Nürburgring. It appears that the muscle car wars are far from over.