A recent dyno run of the new Toyota Supra revealed that it has more power than the Japanese car manufacturer claims and we now have reason to believe that the Supra’s sibling, the Z4 M40i, also has more power than claimed.

The owner of the convertible BMW sports car in the United States recently had the vehicle strapped onto an all-wheel drive dyno in Florida for a series of power runs. Powering the range-topping Z4 is a 3.0-liter turbocharged six-cylinder engine with 382 hp at the crank in U.S.-specification, at least according to BMW.

During the second of three power runs performed, the sports car pumped out an impressive peak of 373 hp and 399.9 lb-ft (540 Nm) of torque at the rear wheels. A peak torque figure of 425 lb-ft (576 Nm) was achieved in the final dyno run.

Also Read: Watch The New Toyota Supra Deliver 339 HP At The Wheels

It’s impossible to know how much of the Z4 M40i’s power is lost through the drivetrain but even if it’s just 10 per cent, that means the car’s engine may actually be pumping out approximately 410 hp and perhaps a little more. That’s a hefty chunk more than the 382 hp officially quoted by BMW. We’ll be interested to see if other Z4 owners achieve similar figures.

Earlier this year, BMW revealed that the most potent of Z4 variants can accelerate to 60 mph (96 km/h) in a brisk 3.9 seconds, down from the 4.4-second time initially spruiked by the automaker prior to the launch of the new Toyota Supra.

Tuning companies should be particularly excited to hear that the Z4 and Supra are more powerful than claimed, knowing full well than the 3.0-liter six-cylinder shared by them is capable of much more power with some modifications.