If you’re in the market for a new BMW M5, then chances are you’ll also be considering Mercedes’ E63 AMG. So, how do these two super-saloons compare?
BMW’s new, fifth-generation M5 can hit 62mph in just 4.4 seconds, thanks to a 4.4-litre twin-turbo V8 that pumps out 552bhp and 502lb ft of torque. What’s more, this torque is available from just 1500rpm, so a gentle squeeze of the throttle is all that’s needed to send the car storming forward, regardless of the gear you’re in.
Like the M5, the E63 uses a twin-turbo V8, but it’s a 5.5-litre that develops 518bhp in standard form and 550bhp if you pay AMG an extra £6495 to increase the turbo boost. Torque climbs, too, from 516lb ft to 590lb ft, helping the E63 get to 62mph in an M5-shading 4.2 seconds. Both cars are electronically limited to 155mph.
Ride and handling
BMW has fitted beefed-up suspension, bespoke adaptive shock absorbers, a chassis-stiffening cross-brace and its clever M Differential, so the M5 handles like no other 5 Series. True, you have to take into account that it’s a big, heavy car when picking your braking points, but it feels extremely taut and composed through bends. Then, hit the motorway, select the softest suspension setting, and comfort is on a par with regular 5 Series models.
With wider axles than the standard E-Class, a bespoke steering rack and three settings for its adaptive suspension, the E63 is agile and easy to drive quickly. In fact, so predictable is its handling that even with all the electronic stability aids switched off, you feel totally in control. As in the M5, the ride is impressively smooth for such a sporty car.
The M5’s fat tyres generate some road noise, and there’s a deep exhaust boom beyond 4000rpm. However, you never get near those revs when cruising in top gear in the UK, and the M5 is brilliant at shutting out wind noise.
While the M5's engine is turbine-smooth, the E63 is more of an old-school muscle car, emitting a deep and languid V8 exhaust rumble even when you're just pottering around town. Road noise is intrusive over coarse surfaces.
Buying and owning
At £73,040, the M5 is a seriously expensive 5 Series, and running costs will be high, despite big gains in efficiency. Where the previous M5 managed an average of just 19.1mpg, this new one should return 28.5mpg when driven carefully.
The E63 is even more expensive than the M5, at £74,695, so it's all the more disappointing that Mercedes charges a further £6495 for M5-rivalling AMG power. Average fuel consumption is almost identical to the M5’s at 28.8mpg.
Quality and reliability
The interior finish isn't really that different to that of a standard 5 Series, but that's no bad thing because it means everything is built to an impeccable standard from first-rate materials.
All of the panels fit together snugly, and most of the materials look and feel smart. However, they’re not as classy as the ones in the M5.
Behind the wheel
Bespoke sports seats and a cluster of buttons that give instant access to the different gearshift speed, suspension stiffness and steering weight settings let you know you’re sitting in something special. Meanwhile, a head-up display and BMW’s intuitive iDrive control system mean you rarely have to take your eyes from the road.
AMG sports seats and an Alcantara-and-leather steering wheel are notable high points. Annoyingly, though, while it looks and feels great, the steering wheel is offset to the left, so you can end up banging your elbow into the centre console. Mercedes’ Comand infotainment system isn’t as user-friendly as BMW’s iDrive.
Space and practicality
A big part of the M5s appeal has always been the way it combines supercar-pulverising pace with everyday usability, and that remains the case with this new one. It’s as practical as any other 5 Series, which means there’s generous space for four in the cabin, and a large, well-shaped boot.
The E63 is another roomy saloon that can seat four in comfort (or five at a push), while its boot can swallow 540 litres of luggage – 20 litres more than the M5’s.
As you’d expect, every M5 comes with heated and electrically adjustable leather sports seats, front and rear parking sensors, cruise control and Bluetooth. The list of standard equipment also includes satellite-navigation, a DAB radio, metallic paint and four-zone climate control.
Almost everything you could want is standard, including luxury automatic climate control, fully electric memory seats, satellite-navigation and a blind-spot monitoring system.
What Car? says…
Both cars are hugely agile, fast and practical, but the M5 gets our vote – just. It’s the more technically advanced car and is that little bit easier to live with. The fact that it’s also usefully cheaper seals the deal.
BMW M5 full review
Mercedes E63 AMG full review
Our reviews are based on hard data and thorough testing in the real world.
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