Recently, we and just about every other automotive publication published and were buzzing about the fact that MotorTrend managed to get numbers from the C8 Corvette that were way above the GM-claimed power numbers for the V8 engine in the car.
According to MotorTrend, the engine would make about 656 hp and 606 lb-ft of torque. That, however, is impossible, according to Motor1. The publication’s writer, Jason Cammisa, details why in his article.
Cammisa points to two main things that disprove MotorTrend’s claims. First, he says the performance times that MotorTrend posted are on par with the other reviews from other publications. Mathematically, the SAE numbers for the C8’s engine of 495 hp and 470 lb-ft of torque make sense for the publication’s claimed quarter-mile run of 11.1 seconds at 123 mph. If the car had the power that MotorTrend claims, it would have posted something like 10.3 seconds at 134 mph.
The second thing he points to is that the Brake Mean Effective Pressure (a measurement of torque per unit displacement) for a naturally aspirated engine of this size would have to be 17.7 bar to make 470 lb-ft. Cammisa says that’s impossible for a naturally aspirated engine of this size.
Cammisa says that the mistake was two-fold. Whoever ran the dyno made a mistake, and then MotorTrend made another mistake by publishing the numbers. It’s an interesting look at the issue, and worth the read. I suggest you check out the link above to see all the rationale.