Could the 2020 Chevrolet Corvette Stingray put out much more than its claimed 495 horsepower and 470 lb-ft of torque. Yes it can, at least according to Motor Trend‘s recent dyno runs with the all-new, mid-engined Corvette. Over six runs, just how much power and torque did the car’s 6.2-liter LT2 V8 manage?
A lot more than Chevrolet claimed, as it turned out.
Now, the explanation of how Motor Trend arrived at their numbers is a bit more nuanced. But let’s talk about those numbers first. Dyno pulls measure the horsepower and torque at the wheels, while official figures are quoted at the crank. Account for a 15-percent drivetrain loss, and you end up with how much power the engine actually produces. On the first run, they managed 558 horsepower and 515 lb-ft of torque at the wheels. That run and the subsequent three were done in fifth gear, which provides the 2020 Chevrolet Corvette the closest to a 1:1 effective gear ratio.
The math translates the engine’s power to 656 horsepower and 606 lb-ft of torque at the crank. You don’t need an advanced degree in mathematics to realize that is way, way more power than the 495 figure we’ve come to accept.
Motor Trend‘s subsequent runs yielded similar results. Runs two, three and four were all done in fifth gear. On the horsepower front, those pulls measured out to 656 hp, 660 hp and 654 hp at the crank, respectively. Even when doing a pull in sixth gear, on Chevy’s suggestion, the number came out to 562 horsepower and 640 lb-ft of torque at the crank.
So what’s going on?
Will all Corvette Stingrays match this output?
It’s worth noting that GM certifies their power and torque figures by SAE (Society of Automotive Engineers) guidelines. More specifically, they use equipment compliant with standards set forth for the J1349 test. The SAE says of the test: “Power and torque certification provide a means for a manufacturer to assure a customer that the engine they purchase delivers the advertised performance.” Engine certification is voluntary, though GM is one manufacturer to use the J1349 standard to certify horsepower and torque.
The SAE database quotes those 495 horsepower and 470 lb-ft torque figures GM released when they revealed the new Corvette. Motor Trend pointed out in their article that the dyno they used is also complaint with SAE J1349 standards. What’s more, they have used it before, and gave a 2020 Ram 2500 Limited as an example. In that test, the truck 6.7-liter Cummins turbodiesel engine managed 890 lb-ft of torque at the crank. That’s not too far off Ram’s 850 lb-ft, and within a reasonable range of variation from engine to engine.
While the exact cause of the discrepancy remains a mystery, the technicians overseeing the six dyno pulls reportedly stuck to SAE testing procedures, same as GM did for its certification.
More tests to come
The folks at Motor Trend came out of this experience puzzled, and it’s easy to see why. The simplest answer to this would be that the engine is, in fact, much more powerful than GM’s official SAE ratings suggest. It’s not completely unprecedented: The 2020 Toyota Supra has managed higher numbers than its official figures would lead you to believe. Still, though, that is too large a discrepancy to dismiss it as a coincidence. Hence, why Motor Trend ran half a dozen dyno pulls.
As more folks get their hands on the 2020 Chevrolet Corvette, surely we’ll see more runs. From there, we’ll have a wider pool of data to see what sort of power we’re really dealing with here. At any rate, the 2020 Chevrolet Corvette is sure to be an exciting proposition, even in “base” Stingray form.
Even if the new Corvette is just marginally more powerful than the official figures, that’s great news. It bodes well for the more powerful versions coming down the line, including the new C8 Corvette ZR1.
Check out Motor Trend‘s full piece here for more technical details. Stay tuned for more 2020 Chevrolet Corvette coverage.