This Is How a Diesel BMW Beats the Petrol Out of a 500-HP M4 Competition

The self-igniting engine is great for trains and tractors, but not so much in arrow-straight dashes. Especially on a rainy track, which is what we have here. But someone did believe that diesel could outrun the sprinter M4 in a leg-stretching event.

The weather reference leaves little to the imagination on who’s the faithful follower of the low fossil fuel – he is coming from across the pond and has invited a former professional racing driver to the duel.

Carwow’s YouTube host, Mat Watson, sits behind the wheel of a BMW diesel from the previous generation. Next to him on the wet airfield in England is Ben Collins, the most famous Stig from Top Gear’s top years.

The professional piston-tamer took the helm of a 503-hp, 479-lb-ft G82 BMW M4 Competition. That’s 510 ps and 650 Nm on a 1.8-tons car. Three liters, six aligned cylinders, 279 hp/ton (283 ps/ton), rear-wheel-drive, torque converter, eight-speed automatic, 3.6 seconds in the zero-to-sixty sprint (0-97 kph). Not exactly a walk in the park for a same-category competitor of the M4 Competition.

That would be a BMW 430 diesel from yesteryear… almost. The regular mileage-braving Bavarian got a gym treatment and came out as Hulk. Three liters, six pistons arranged precisely in the same architecture as the M4 – the traditional straight. To make things interesting, the drivetrain is not much different either: eight-speed auto, torque converter, all to the rear wheels.

This is where things go sideways for the diesel: normally, that model produces 255 hp (258 ps) and 413 lb-ft of torque (560 Nm). Half as much power when put next to the M4 Competition rival, and 5.4 seconds for the 0-60 mph.

But abnormally, this particular example has received Iron Man’s arc reactor. Consequently, it still can not fly. But it now makes 750 lb-ft (1,017 Nm) of crank-bending brute force and 456 hp (462 ps). Not too bad, but things get spicier.

The diesel is lighter than the M, at 1.6 tons, which returns a power-to-weight ratio of 282 hp/ton (286 ps/ton). It even outpowers the M4 – not by much, just marginally, but still. Not to disregard the M4’s other mechanical and electronic advantages, but it looks like a balanced match.

The drag race is more like a drag rage – tons of wheel spin due to the wet and slippery tarmac. And, perhaps not that surprisingly, the torquey old 430d bimmer inches ahead of the track-proud M4 at the start. It can't keep its pace, however, and crosses the line second.

The second race sees a comeback against the athletic Motorsport red-purple-and-blue-blooded petrol-powered coupe. The underdog bites hard and claims the win. Because the race follows a best-two-out-of-three scoring system, the decider is swift and shocking: the diesel pulls the M4 across the 1,320-foot sprint.

A fourth leg is played in the spirit of fair play, but it only confirms the M4's demise. The diesel is one-tenth of a second faster in the 402-meter race, with a 12.5-second win. The second stage is pure M4 revenge, taking all rounds in the rolling race.

The sporty BMW even throws out a bit of a dramatic performance, briefly spinning its wheels out of grip and fishtailing in the rain. It wins thanks to its top-end power reserve and better high RPM power band distribution across gear shifts.

It also wins the braking test without a shadow of opposition from the diesel. The latter’s brakes are so worn out that regular stops seem like an adventure. However, for its rock-crushing torque figures, the otherwise-low-caste tenure is to be reckoned with.