This BMW E91, fitted with a 3.0-litre diesel engine and a single turbocharger, arrived with existing changes to its exhaust and engine management systems. The DPF internals had been removed, the intake swirl flaps were absent, and the catalytic converter remained in place. The car also had a previous ECU calibration that its owner had not known about.

Before the new calibration, the car was checked on a dynamometer to assess the existing software and hardware setup. That initial reading described the vehicle in its current condition, rather than in factory specification.

After the inspection, the ECU calibration was adjusted for the standard engine and turbocharger, and the car was tested again on the dyno and on the road. The video shows a small amount of smoke under high load; the work also focused on increasing output while keeping engine response predictable.