When driving the latest BMW M550d xDrive you don’t really feel that what it needs is extra power and torque, but that has never stopped tuners from turning things up to eleven. German tuner mcchip-dkr has unlocked more of everything from the quad-turbo 3.0-liter straight-six, and it now offers two stages of power.

In stock form, the M550d makes 396 horsepower and 560 pound-feet of torque, which is good for a sprint time from naught to 62 mph / 100 km/h in 4.4 seconds.

Then there’s the (€1,670 / $1,930) stage two kit which further increases power to 508 horsepower and torque to 638 pound-feet and if the first kit doesn’t drop its sprint time to 62 mph / 100 km/h under the four seconds mark, then this second one surely will. Top speed also gets an extra nudge, to 183 mph (295 km/h).

In the standard car, full torque is not available in the first gears, so mcchip-dkr could have tweaked this with their revised software - BMW probably did that to protect the transmission and all-wheel drive components from excessive wear, but it would be interesting to see what an M550d xDrive does when it unleashes all available torque from standstill - it has no reason not to light up all four wheels and power away in a plume of tire smoke with all electronic aids disabled.

The car in the photos also features additional modifications on top of the remap job.

Further reading

Read our full review on the 2018 BMW M550d xDrive.

Read our full driven review on the 2018 BMW M550d xDrive.