A new horsepower war is brewing and could see Chevrolet’s new Camaro ZL1 released with more grunt than was originally planned. The ZL1 (pictured) isn’t expected in American car dealerships until early next year, but new reports are stating that power output has been bumped up to more than 570 hp (425 kW).

When the car was officially debuted at the Chicago Auto Show, GM said the supercharged 6.2-litre engine would have a max power output of approximately 550 hp (410 kW). That was until word came out that the 2013 Ford Mustang Shelby GT500 was expected to utilise  a supercharged 5.8-litre V8 with up to 620 hp (462 kW). With Ford now bringing a machine gun to a knife fight, Chevrolet is left with little choice but to upgrade its hardcore ZL1, just to put up a fight.

We will have to wait and see how these two old enemies battle it out, but this horsepower war is only just beginning.