Driven: Mercedes E63 AMG

AMG E-class ditches 6.2 V8 for latest twin-turbo lump

There was an advert on telly a few years ago where a young girl was asked whether she preferred 'Daddy' or 'Chips'. A tough call, naturally, but after a day's umm-ing and ahh-ing she plumped for the potato-based option. I feel the same way about the Mercedes E63 AMG. Because the fastest E-class in town has just ditched its naturally aspirated 6.2-litre V8 in favour of a 5.5-litre twin-turbo V8, the newest kid on the AMG block, and I am finding it one heck of a difficult decision to choose between the two.

On paper, and pragmatically speaking, the new direct-injection 5.5-litre twin-turbo engine is obviously the way to go, of course. It's got the same power (518bhp), but more torque over a wider rev range (516lb ft at 1750-5000rpm versus 464lb ft at 5200rpm), and it's cleaner, greener, and leaner (22 per cent leaner, in fact) - giving a perfectly respectable EU combined cycle figure of 28.8mpg.

The 6208cc naturally aspirated V8 is therefore an officially endangered species. It survives now only in the various C63 AMGs (AMG engineers can't squeeze the turbo motor into the C-class's engine bay) and in the SL63 AMG (which is not all that long for this world). Even the SLS motor, whose swept capacity is identical, is no more than a distant cousin, getting the designation M159 rather than the outgoing E63's M156 coding.

But there's no point in being maudlin. The new engine is here, and it's received pretty much rave reviews in the two cars it's been put to use in thus far (the CLS63 AMG and the S63 AMG), so it's hard to imagine that the re-engined E63 AMG is going to be anything other than point-blank stunning. Especially since changes to the already sweet chassis are limited to necessary suspension tweaks to cope with the different weight of the new engine.

So it proves. Okay, the cars we tested (both on the Paul Ricard circuit in southern France and on the surrounding roads) were fitted with both the performance pack, bringing peak power up to 549bhp and torque up to 590lb ft, and the driver's package, which lifts the top speed to 186mph. But even so the pace and sheer breadth of grunt of this new engine is deeply memorable, especially considering that it must haul around 1840kg. And more like two tons with a chunky Riggers and passenger on board.

On the road, the extra torque is immediately apparent, with whole-line-of-traffic urge on tap more or less immediately. This is helped, at least in the sportier of its automatic guises (two out of the four modes), by the MCT-7 gearbox, whose single wet clutch and absent torque converter help keep changes swift, decisive and sharp, and which responds intuitively and intelligently to your right foot. In fact our only criticism of the gearbox is that it's still a mite more hesitant than full-house twin-clutch efforts (and the better autos) when you really want split-second, on-demand, manual-style gearchanges.

The new variable-ratio electrically assisted steering rack (no hydraulics here anymore, remember) feels well weighted and linear, allowing you to pitch into corners and place the car with great confidence, while an essentially benign chassis helps you get on the power nice and early, all the better to enjoy that V8 bellow. And that,although muffled a touch by the turbos, now has a lovely woofle to it which, dare we say it, makes it sound a touch more cultured than the old car.

On the circuit, however, it is genuinely hard to tell that you are being propelled along by a turbocharged engine, so smooth and linear is the acceleration. The AMG people wouldn't let us play with the ESP switched off (probably understandable given the high-speed nature of Paul-Ricard), but the Sport setting in the ESP does allow you a certain amount of slip in both latitude and longitude.

From what we can tell, the E63 remains a thoroughly well-balanced companion through faster corners, while the steering (now electro-mechanical, remember) felt faithful, quick-witted and direct. There's a wee bit of push-on understeer in slower corners, but this is a heavy car so we'll forgive it that - and it's something that would be easily dialled out should you be allowed to switch off the ESP entirely.

We suspect, however, that few people are going to take their E63 onto the track. So while it is nice to know that the E63 can pick up its skirts and skip around a circuit with the best of 'em, it's even nicer to that the new engine and steering merely make a cracking car even better, especially since the £73k price tag of the old car isn't likely to rise significantly. So, 'Daddy' or 'Chips'? If the chips happen to come with a pair of turbochargers, definitely chips.

Key data at a glance:

	E 63 AMG	E 63 AMG Estate
Cylinder arrangement	V8	V8
Cylinder angle	90°	90°
Valves per cylinder	4	4
Displacement	5461 cc	5461 cc
Bore x stroke	98.0 x 90.5 mm	98.0 x 90.5 mm
Cylinder spacing	106 mm	106 mm
Compression ratio	10.0:1	10.0:1
Output	386 kW (525 hp) at 5250-5750 rpm 410 kW (557 hp at 5250-5750 rpm*	386 kW (525 hp) at 5250-5750 rpm 410 kW (557 hp at 5250-5750 rpm*
Output per litre	71 kW (96 hp) 75 kW (102 hp)*	71 kW (96 hp) 75 kW (102 hp)*
Max. torque	700 Nm at 1750-5000 rpm 800 Nm at 2000-4500 rpm*	700 Nm at 1750-5000 rpm 800 Nm at 2000-4500 rpm*
Torque per litre	128 Nm 146 Nm*	128 Nm 146 Nm*
Maximum engine speed	6400 rpm	6400 rpm
Mean pressure	18.5 bar 20.8 bar*	18.5 bar 20.8 bar*
Engine weight (dry)	204 kg	204 kg
Power/weight ratio	0.39 kg/hp 0.36 kg/hp*	0.39 kg/hp 0.36 kg/hp*
Fuel consumption NEDC combined	9.8 l per 100 km	10.0 l per 100 km
CO₂ emissions	230 g/km	234 g/km
Acceleration 0 - 100 km/h	4.3 s 4.2 s*	4.4 s 4.3 s*
Top speed	250 km/h*	250 km/h*