This twin-turbo BMW E61 535d received a Stage 1 engine calibration and Stage 2 software for its 6HP automatic transmission using xHP. The transmission control unit was unlocked before the new software was written.

Before tuning, the dynamometer recorded 255 hp and 527 Nm, below the factory figures quoted in the video: 272 hp and 560 Nm. The stated post-tune result is about 310 hp, with the gain described as almost 60 hp and approximately 130 Nm.

The video also says that if the car’s baseline dyno result had matched its factory rating, the calculated target would have been about 330 hp and 690 Nm. Those are not confirmed results for this car: its initial dyno reading was below the nominal figures. The theoretical target should therefore be kept separate from the measured result for this vehicle.

Stage 2 software was written to the transmission, but the video does not provide long-term test results. Changes to the DPF and other emissions-control systems had been made previously; they are not described as a separate repair task during this visit.