Trust us when we say this used to be a plain BMW 2 Series Coupe in the humble 220d specification. It now has the heart of an M Performance diesel SUV as the original four-pot engine has been yanked to make room for another diesel, much larger and with a lot more turbochargers. Meet the unofficial M2 50d, equipped with an inline-six, tri-turbo diesel engine borrowed from an older X5 M50d.

The impressive build represents the work of Gary Martins, a former BMW Master Technician, who is now running his own business dubbed Grease Monkey Motors. Suffice it to say, he's a big fan of BMW and knows his way around them. The oil-burning M2 might seem like sacrilege to M fans, but with the company having a history of M Performance diesels, perhaps it's not such an outlandish idea.

The bigger engine was mounted without requiring any modifications to the body. Having received the nitrous treatment as well as water-methanol injection, the 3.0-liter diesel now pumps out 583 horsepower (435 kilowatts) and 1,070 Newton-meters (789 pound-feet) of torque. That's quite the bump from the original 381 hp (284 kW) and 740 Nm (546 lb-ft).

The 220d donor car made way for a much more aggressive-looking coupe with the front bumper borrowed from the M2 Competition. A quad exhaust was also added to mimic the look of a real M2, while the carbon fiber M Performance rear wing accentuates it's no longer a regular diesel 2 Series Coupe. Gary Martins explains the rear fenders had to be widened to fit the bigger wheels, while the rear bumper and front fenders come straight from an M2.

A custom-built carbon fiber hood hides the diesel beast within, and the trunk lid is also made from the same lightweight material. Chunky front brakes borrowed from the M5 (F10) and rear ones from an M4 provide the necessary stopping power following the engine upgrade. Speaking of which, the tri-turbodiesel now works with a transmission originating from a 330d but modified to handle the extra torque.

The list of changes goes on forever as a 330d also lent its differential and a shortened prop shaft. Gary Martins mentions the driveshaft comes from an M135i. Inside, there are M3-sourced front seats and a roll cage replacing the rear bench. As shown in the tail-happy sequences, the M2 50d remains a rear-wheel-drive machine, unlike the official M50d-badged cars which all have xDrive.

It can be used not only as a daily but also as a track car and even for drag racing with little modifications. The high-performance diesel M2 will be put through its paces in early September during the 11th edition of the Simola Hillclimb event in Knysna, South Africa.

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