Last year there was a big brouhaha when BMW proudly revealed a 2.4-ton G90/G99 M5 with a plug socket. ‘Most controversial M car ever?!’ screamed certain headlines, wholesale failing to recognise that BMW routinely uses M cars to send its faithful into a frothing frenzy. And the apex troll was actually this, the E60 BMW M5.
BMW had already replaced the effortlessly handsome E39 M5 with a car that looked like a dragon wearing cat eye glasses. It festooned the interior with early iDrive, the single most mental health damaging invention to inhabit a screen until the creation of Twitter.

And it replaced a worldie of a powertrain – the 4.9-liter M division V8 and manual gearbox – with a 5.0-liter V10 attached to a seven-speed sequential manual gearbox with five shift speeds. And three differential moods. And three power outputs to select. Sure, it swelled power by 100 horses up to 500hp, but has any car ever followed up such a surefire classic with so many shots in the dark?
OTHER STORIES YOU MIGHT HAVE MISSED:
Confirmed: Mercedes-Benz is bringing back the G-Class Cabriolet
Nissan completes manufacturing line integration in Thailand
Like a couple of more exotic V10s we’ll reacquaint ourselves with shortly, this unlikely V10 employment owed its very existence to an ungarlanded motorsport FUBAR. BMW had been supplying V10s to Williams from 2000, challenging the Schumacher/Ferrari dominance, but the relationship had soured by 2005 so BMW bought the Sauber team instead. It won just one race before exiting, trophy cupboard almost empty, in 2009.
But naturally, the M5 project planners had been tasked with aligning their ultimate super sedan with the single seater formula long before any of that disappointment. What they came up with remains one of the most out of place engines ever to power a leather smothered family four door.

The S85B50 engine weighs 240kg and develops 100hp per liter. It’s all aluminium (save for a forged steel crank) and revs to 8,250rpm. You only get a thimbleful of torque and have to wait until north of 6,000rpm before it’s available for use overtaking. So for application in a burly bizznuss express, it’s sort of hopeless, especially when allied to a transmission that cooks its own clutch unless it’s set to DEFCON 1 max attack.
And yet... it’s now a cult classic. Jarring in 2005, but utterly stupefying today (and yet two thirds of a tonne lighter than today’s M5, and bizarrely elegant to look at for what was once the apex of the tech obsessed, overstyled M car.) Though the core design of the V10 was shrunk by a fifth for the E92 M3’s demonic V8, the V10 only lived for one generation, before bowing out in 2010. Wonder if time will turn the skepticism over today’s M5 into this much future adoration?
BMW M5 (E60)
Engine: 5.0L V10
Power: 500hp
Torque: 520Nm
Transmission: 7-speed SMG/6MT (US market only)
Layout: RWD
Performance: 0-100kph in 3.4secs, 250kph (electronically limited)
Weight: 1,830kg
NOTE: This story first appeared on TopGear.com. Minor edits have been made.