BMW has been known to be conservative with its horsepower ratings. A lot of the automaker’s vehicles produce more power than the brand lets on. It looks like the same is ringing true with the new BMW M5.

The F90 M5 is the most expensive and fastest vehicle in the brand’s history to wear the iconic nameplate. Power for the sedan comes from a 4.4-liter twin-turbocharged V8 that produces 600 (447 kW) horsepower and 553 pound-feet (748 Nm) of torque. Those figures, though, are from BMW and, as the dyno run below shows us, should be taken with a massive dose of salt.

It actually produces a lot more

IND Distribution (via BMW Blog), an Illinois-based tuner that specializes in making fast BMWs, put a M5 on a dyno and got some surprising numbers. The tuning company followed the proper break-in procedures, waiting for the vehicle to cover roughly 1,200 miles, and let the twin-turbo V8 loose. Surprisingly, they recorded a figure of 625 hp (466 kW) and 608 lb-ft (824 Nm) of torque at the wheels.

IND’s best run took place in fifth gear with the BMW in its Sport Plus setting. The tuning company also did a run with the sedan in its Eco Mode and found that the performance vehicle only reduces its output by approximately 15 hp (11 kW). When put into Sport Plus mode and its rear-wheel-drive setting, the M5 maxed out at 152 mph (244 kp/h) and generated a maximum output of 593 hp (442 kW) and 578 lb-ft (783 Nm) of torque.

The findings are good news for enthusiasts waiting to get heir hands on a M5 that’s equipped with the Competition Package, as that vehicle is expected to put out 616 hp (459 kW). It’s also good news for tuners, as the M5 becomes a real beast with a few performance parts.