BMW 5 Series M550i 2017 first drive

The not-quite M5, sharing its bigger brother’s combination of a twin-turbocharged V8 engine and all-wheel drive, but with less power and less performance.

The M550i is one of BMW’s M Performance products, but neither it or its diesel-powered M550d sibling will be sold in the UK, the official logic being that there isn’t enough space between the 540i xDrive and the full-fat M5.

While unable to match the raw firepower of the 600hp M5, the M550i’s 4.4-litre V8 produces an entirely respectable 456hp and – thanks to the magic of all-wheel drive and the weight saving made to this generation of 5 Series – dispatches the 0-62mph dash in a claimed 4.0sec, which is faster than the last-generation F10 M5 could manage. An eight-speed automatic transmission is standard, along with a rear-biased all-wheel drive system, although one that lacks the M5’s ability to turn itself rear-drive only.

The engine is definitely the star attraction. The big V8 has an abundance of brawn – generating peak torque from just 1800rpm – and also delivers plenty of character.

It’s well-mannered under gentle use, although producing little more than a muscular hum, but it’s also happy to lift its skirts at a moment’s notice, pulling cleanly all the way to the 7000rpm redline and producing a nicely judged amount of eight-cylinder snarl when asked to do so. The gearbox helps out with intelligent part-throttle shifting to help wake the engine and impressively rapid ratio swaps at higher commitment levels. In terms of straight-line pace and soundtrack, it comfortably outguns the Mercedes-AMG E43’s turbocharged V6.

But the M550i struggles when asked to deliver on the rest of the sports saloon experience. In essence, it’s a very fast version of the standard 5 Series - a car that already feels a fair bit easier-going than its predecessors - rather than a not-quite M5.

Suspension is soft and, despite the presence of adjustable dampers, struggled to maintain body control over rougher road surfaces, even in the firmest Sport mode; there’s a surprising amount of body roll as well. Grip levels are predictably high, but the handling balance feels nose-heavy under hard use and, although accurate, the steering allows pretty much no sensation regarding the road surface through its syrupy assistance. It’s effortlessly fast and very secure, but there are none of the push-harder vibes that the presence of an ‘M’ badge might legitimately lead you to expect.