Now that the 2020 Corvette C8 is officially out in the world, all us auto journalists finally have a chance to poke and prod it to see what makes it tick. Motor Trend took the opportunity to put the new mid-engine Chevrolet Corvette on the dyno to see what sort of numbers it would post, and long story short, the results are unbelievable.
After acquiring a pre-production build for testing purposes, Motor Trend ran six dyno pulls with the 2020 Corvette. The numbers from the first run left the testers floored—558 horsepower and 515 pound-feet of torque at the wheels. Holy moly.
Those are huge numbers, far above Chevy’s claim of 495 horsepower and 470 pound-feet of torque with the optional performance exhaust system. What’s more, it has to be said that the manufacturer’s claimed numbers were certified by the Society of Automotive Engineers (SAE), which conducts much far rigorous testing then the runs performed by Motor Trend.ù
After doing a few more runs and talking to various experts, Motor Trend was stumped. The testers also strapped up a 2020 Ram 2500 to see if the dyno was wonky, posting 760 pound-feet of torque, a bit closer to Ram’s claimed 850 pound-feet of torque.
After all the runs, the 2020 Corvette’s lowest numbers were 478 horsepower and 536 pound-feet of torque.
Road & Track’s Jason Cammisa ain’t buying it. In a post to Instagram, Cammisa laid out some math and specs on why Motor Trend’s numbers don’t make any sense.
We agree that the Motor Trend numbers don’t really add up. While manufacturers do slightly underrate power and torque numbers from time to time, the discrepancy here is far above anything like that. While it’s possible the tester was simply tuned to produce more power, we think the much likelier suspect is the dyno itself.
Live to dream.. the stock 2020 Chevrolet C8 Corvette Z51 Stingray makes 558 hp at the wheel meaning it generates possibly as much as 650 hp; but does it really matter, we all know the C8 Corvette is a true beast and with cylinder deactivation will still get over 30 mpg mileage or that with the integration of the Chevy Bolt EV engine driving the front wheels to create a hybrid, the C8 Corvette could easily get over 40 mpg mileage.
It generally GM under rates their engine. Often they produce more than advertised.
Also GM will teak the power till the start production and often up the power officially by release of the new car.
Also with unused units on dealer lots they may be holding back a little to sell off the Z06/ GS units.
What we should understand here is if it is putting out this much power and the reviews say the chassis is not even feeling near it’s limits is telling how good this car can and will be in the future with even more power and more suspension tuning.
Any engine will make a huge power at a temperature of 60 degrees F. Any temperature above or below that reduces HP. Also, did they use extreme high 115 octane gasoline, used for racing? Did they drain the oil and put in 0W20 full synthetic oil to reduce drag on the rotating parts to a minimum? Was the engine torn down before the dyno tests to blueprint it and possibly raise the compression ratio by shaving the heads a few thousands of an inch? I put some dry ice chunks in my gas tank to make a run at the drag strip and also put some dry ice on the intake manifold one very hot summer day to get max performance for the few seconds run, just like a dyno only runs for a few seconds when testing. Was the dyno room reduced to a super low temp, so any fresh air going into the intake manifold, would still be cold, to produce max power? I would do all the above to get max power for a few seconds.
Motor Trend not knowing how to operate a dyno doesn’t mean the Stingray makes 550+bhp. 495 bhp is the lowest a new C8 will ever make from the factory, and no more than 2% higher. It may gain a bit once it’s broken in.
Cammisa was close. Naturally aspirated [top tier racing] engines have a physical limit of 16.5 bar BMEP on gasoline. The Stingray makes 11.1 bar at peak HP, and 13.0 bar at peak torque. The Porsche GT3 makes 14.1 bar at peak hp, and 14.5 bar at peak torque.
GM does not underrate, they are at most rounded down. SAE testing does yield slightly lower numbers than real world or Dyno and this was a combination of those factors a d either Dyno operator error or out of calibration. Maybe some Motor Trend click baiting too.
Case in point the Camaro V6 was 304 HP in 2010 and then advertised at 312 in 2011 If I recall the right years. The folks asked the GM engineers what changed and the drive line engineer said nothing and the power was already there just not advertised. Both engines were listed with SAE paperwork too.
We need to remember Ford has been busted several times for advertising more power than they were producing. They got in a lot of trouble over this. GM on the other hand since the 90’s has generally under rated engines in advertising to be safe and for future changes.
Even my 85 Pontiac was up 5 HP over the later years yet nothing changed in those 4 years.
As for tuners and Dynos. Most are not calibrated to exact numbers. The shops often do not look for exacting numbers as much as gains or losses in the changes they make. The accurate numbers are often the changes.
Also some like Dynajet Dynos are more accurate than others like the Mustang Dyno. Then reproducing the same conditions can vary results today too.
Comments
Live to dream.. the stock 2020 Chevrolet C8 Corvette Z51 Stingray makes 558 hp at the wheel meaning it generates possibly as much as 650 hp; but does it really matter, we all know the C8 Corvette is a true beast and with cylinder deactivation will still get over 30 mpg mileage or that with the integration of the Chevy Bolt EV engine driving the front wheels to create a hybrid, the C8 Corvette could easily get over 40 mpg mileage.
The Ram numbers are pretty bang on for drivetrain loss to the wheels versus manufacturer spec sheet engine numbers.
Definitely something strange with the C8.
It would be a better sales pitch to change the HP rating to 550.
The Z06 buyers will probably pull the trigger on the Stingray.
It generally GM under rates their engine. Often they produce more than advertised.
Also GM will teak the power till the start production and often up the power officially by release of the new car.
Also with unused units on dealer lots they may be holding back a little to sell off the Z06/ GS units.
What we should understand here is if it is putting out this much power and the reviews say the chassis is not even feeling near it’s limits is telling how good this car can and will be in the future with even more power and more suspension tuning.
Hello Scott. Are you upgrading from your GMC Acadia to Corvette?
Any engine will make a huge power at a temperature of 60 degrees F. Any temperature above or below that reduces HP. Also, did they use extreme high 115 octane gasoline, used for racing? Did they drain the oil and put in 0W20 full synthetic oil to reduce drag on the rotating parts to a minimum? Was the engine torn down before the dyno tests to blueprint it and possibly raise the compression ratio by shaving the heads a few thousands of an inch? I put some dry ice chunks in my gas tank to make a run at the drag strip and also put some dry ice on the intake manifold one very hot summer day to get max performance for the few seconds run, just like a dyno only runs for a few seconds when testing. Was the dyno room reduced to a super low temp, so any fresh air going into the intake manifold, would still be cold, to produce max power? I would do all the above to get max power for a few seconds.
Read the original story and stop overthinking this.
They did simple dyno pulls and got varying results.
All dyno’s are not calibrated either but it is still safe to say it makes more than published. That has been something documented that GM does.
Motor Trend not knowing how to operate a dyno doesn’t mean the Stingray makes 550+bhp. 495 bhp is the lowest a new C8 will ever make from the factory, and no more than 2% higher. It may gain a bit once it’s broken in.
Cammisa was close. Naturally aspirated [top tier racing] engines have a physical limit of 16.5 bar BMEP on gasoline. The Stingray makes 11.1 bar at peak HP, and 13.0 bar at peak torque. The Porsche GT3 makes 14.1 bar at peak hp, and 14.5 bar at peak torque.
GM does not underrate, they are at most rounded down. SAE testing does yield slightly lower numbers than real world or Dyno and this was a combination of those factors a d either Dyno operator error or out of calibration. Maybe some Motor Trend click baiting too.
Case in point the Camaro V6 was 304 HP in 2010 and then advertised at 312 in 2011 If I recall the right years. The folks asked the GM engineers what changed and the drive line engineer said nothing and the power was already there just not advertised. Both engines were listed with SAE paperwork too.
We need to remember Ford has been busted several times for advertising more power than they were producing. They got in a lot of trouble over this. GM on the other hand since the 90’s has generally under rated engines in advertising to be safe and for future changes.
Even my 85 Pontiac was up 5 HP over the later years yet nothing changed in those 4 years.
As for tuners and Dynos. Most are not calibrated to exact numbers. The shops often do not look for exacting numbers as much as gains or losses in the changes they make. The accurate numbers are often the changes.
Also some like Dynajet Dynos are more accurate than others like the Mustang Dyno. Then reproducing the same conditions can vary results today too.