The Mercedes-AMG GT 63 S is about as serious as performance sedans can get but the one featured in this video is more impressive than most.

As standard, the GT 63 S’s 4.0-liter twin-turbocharged V8 engine pumps out 630 hp and 664 lb-ft (900 Nm) of torque. The owner of this example clearly wanted some extra grunt and has had a pair of new turbochargers fitted alongside an Akrapovic exhaust and some software tuning for the engine that increases power to 870 hp and 774 lb-ft (1,050 Nm). Eager to see just how fast the modified sedan is in the real world, Daniel Abt lined it up against a McLaren 765LT.

Watch Also: Could The McLaren 765LT Actually Be Quicker Than The P1?

The British car manufacturer claims that the 4.0-liter twin-turbo V8 of the 765LT delivers 755 hp and 590 lb-ft (800 Nm) of torque but dyno tests have revealed it it could be closer to 850 hp. The McLaren also weighs roughly 2,000 lbs (907 kg) less than the Mercedes.

In the first race, it is the Mercedes-AMG GT 63 S that gets the far superior launch thanks to its all-wheel drive system. It leaves the McLaren for dead as the 765LT struggles to put its power to the ground and initially seems like it will walk away with the win. However, once the McLaren overcomes its traction issues, it rockets past the Mercedes. In the test, the Mercedes needed just 3.09 seconds to hit 60 mph (96 km/h) while the McLaren recorded a time of 4.0 seconds.

In the second race and with the tires of both cars nice and warm, Abt gets a better launch in the McLaren and is almost able to match the Mercedes off the line, allowing him to take victory without breaking a sweat.