This is the 2011 Mercedes E63 AMG, the hottest Mercedes E-class. It looks the same, but those 'V8 biturbo' badges on the front wings give the game away: the old naturally aspirated 6.2-litre V8 has given way to a new 5.5-litre V8 twin turbo. This makes the E63 the last AMG to get the 5.5 part way through its life cycle; both S63 and CL63 have already been upgraded, the CLS63 got the engine from new, and the SLS supercar and C63 retain the existing 6.2-litre.
Why swap the engine? The Mercedes E63 AMG was already were good indeed...
It's primarily down to efficiency: the 5.5-litre is 22% more fuel efficient than the old engine, and produces 65g/km fewer too (230g/km total). But there are performance gains too, especially if you spec the optional Performance Package. Around 30-40% of customers will do just that, despite the circa £6k price tag. So, as standard the power output remains the same at 518bhp, but torque climbs from the 6.2's 464lb ft to 516lb ft.
Spec that Performance Pack and you'll get 549bhp and 590lb ft, yet the economy figures remain the same.
Are there any other changes?
The hydraulically assisted steering has been replaced by an electro-mechanical set-up (i.e. the hydraulic assistance is powered electrically, rather than driven off the engine). This alone yields a 1-2% fuel saving. A stop-start system is also standard, and cuts the engine at the traffic lights, then seamlessly and automatically restarts it when you move off again.
Other than that there's a very small recalibration of the seven-speed transmission to complement the new powerplant, plus there's a revised steering wheel and gear shifter.
How does the new twin-turbo E63 drive?
It's brilliant. We're driving a Performance Pack model, so the differences are even more pronounced versus the old 6.2: it pulls much more lustily from 1000rpm and absolutely wallops through the mid-range.
Those who feared the E63's character would die along with the naturally aspirated engine will be glad to learn that the bomb-detonating-under-water thud that heralds start-up is alive and well, the turbos haven't muted the familiar AMG V8 muscle car burble, the throttle response is keen and there's still a nice wump on full-throttle upshifts.
If you've spent a lot of time in the 6.2 (I have, having run a E63 Estate for a good few months now) you'll notice that there's no real point in chasing the redline anymore: the engine's work is done by around 5500rpm, so the tingle of the old car pulling strongly beyond that is gone. Furthermore, if you do select Manual mode and really wind the car out, there's an extended pause when you pull for the next gear, as if you've triggered a split-second fuel cut-off.
You might also sometimes find yourself denied a downshift when driving really hard, simply because the engine doesn't rev as high. No doubt this will take just a short period of acclimatisation to be accustomed to.
How does the rest of the car feel?
The new steering system is really impressive, giving a well-judged blend of weight and linearity that makes you feel connected to what the front tyres are up to. The independent electric assistant also means it can be usefully lighter at very low driving speeds, like mini roundabouts and car parks, for instance.
The steering doesn't bristle with quite the same level of feedback as the old 6.2, but that doesn't really detract from the driving experience.
The E63 is a big car, so it can't match the agility of the C63, but the good body control and strong front-end grip are still very much in evidence, while, thanks to our car's Performance Pack, the rear end is even more exploitable and adjustable. That's something I preferred on baking hot French roads, but how it will translate to wet British roads remains to be seen.
Verdict
In terms of absolute purity, the old 6.2 does edge the new car, but it's a small difference and one that doesn't fundamentally affect the inherent brilliance of the E63. It's still an utter thrill to drive, and it's faster in the real world too. A drive in a similar, non-Performance Pack CLS suggests that even the standard car will be
significantly quicker than before, too, thanks to all that mid-range turbo torque.
Then you factor in the fuel savings. It'll cost you approximately £500 less to fuel over 10,000 miles and the fact that you'll have to fill the tank less frequently and, well, you can't really argue.
