As with the arrival of any new sports car, the 2016 Camaro has caused something of a feeding frenzy in the performance aftermarket. Shops across the country are strapping the new Chevy pony car to their dynamometers in a bid to keep GM honest with its stock horsepower ratings, as well as to give themselves a baseline number that they can build on.

Jannetty Racing of Waterbury, Connecticut is among the first shops in the country to get a 2016 Chevy Camaro SS on the dyno, putting 416 horsepower and 430 lb-ft of torque down at the wheels. Over in Texas, Hennessey Performance Engineering had even better luck, with its stock 2016 Camaro laying down 431 horsepower and 427 lb-ft of torque. Did GM not just underrate the new Camaro, but make it more powerful than the Corvette too?

Horsepower ratings can be affected by a number of factors, from air density and ambient temperature to the kind of dyno being used. Rated at 455 horsepower at the crank from the factory, and assuming a 15 percent drivetrain loss, which is typical for rear-drive sports cars, the LT1 V8 should “only” be putting about 400 to 410 horsepower down at the wheels. Jennetty’s numbers are within the one percent allowance of SAE ratings, but Hennessey’s 427 horsepower rating is three to five percent more than what a stock Corvette is putting down.

If the 431 number is consistent, that’d put the 2016 Camaro SS closer to 490 horsepower than 455, as per its rating. Even the 414 horsepower run would suggest a power level closer to 475 than 455, and same with the 430-ish lb-ft of torque. A perecent drivetrain loss puts the torque rating within spitting distance of 500, a big jump from the 460 lb-ft the LT1 is actually rated at.

Are these just factory freaks, refinements made to the LT1 engine, or has GM purposefully underrated its engines once more?