Car reviews - Mercedes-Benz - CLS-class - CLS63 AMG 4-dr coupe
24 Oct 2006
By CHRIS HARRIS
SUPERCHARGERS are out as Mercedes-Benz relaunches its answer to BMW’s M cars, as well as the Audi RS series, with the AMG 63 range.
Four disparate models are now available, with variations of an all-new V8 engine and seven-speed automatic gearbox combination.
In order from the lowest price is the W164 ML 63 AMG 4WD wagon, C209 CLK 63 AMG coupe and W211 E 63 AMG and C219 CLS 63 AMG sedans, with the CLK and E also offered in A209 convertible and S211 wagon iterations respectively.
A W221 S-class variant – the S 63 AMG – is scheduled to slot into the series in the middle of 2007, along with the C216 CL 63 AMG and W251 R 63 AMG, bringing the 63 AMG total to seven for now.
Other AMG models, including the new $450,000, V12-powered S 65 and W203 C55 AMG sedans, will remain on sale.
At the heart of AMG 63 range is a new 6.2-litre V8, a 90-degree twin overhead cam V8 displacing 6208cc, four valves per cylinder, a 102.2mm bore and 94.6mm stroke, and a compression ratio of 11.3:1.
Mercedes says that German law insists that manufacturers round the figure up to the next whole number, hence the 6.3-litre, or ‘63’ tag.
The power output for most AMG 63 models vary ML: 375kW at 6800rpm CLK: 354kW at 6800rpm CLS and E: 378kW at 6800rpm and S: 386kW at 6800rpm.
Curiously though, the torque top is the same for all – 630Nm at 5200rpm (5000rpm in the CLK), with a maximum engine speed of 7000rpm.
Mercedes-Benz describes this powerplant as the first in the world “… to combine the high-revving concept with a large displacement.” Its power-per-litre output is 62.2kW, while delivering 101.5Nm per litre.
The company also claims that the 6.2-litre V8 delivers 20 per cent more torque than comparable naturally aspirated engines with a similar power rating. At 2000rpm there is already 500Nm on offer.
Developed and hand-built at the wholly owned DaimlerChrysler AG subsidiary in Affalterbach (near Stuttgart) in Germany, the V8 is exclusively AMG’s, and shares nothing with any existing production engine from Mercedes-Benz.
Manufactured from high-strength aluminium, it was devised using the company’s extensive motorsport experience and expertise.
Reflecting this is the vertical arrangement of the intake and exhaust ports that, in conjunction with an AMG-first trick-new dual length variable intake manifold – provides highly efficient cylinder charging.
High engine speeds are possible due to the stiff valve train achieved through the use of bucket tappets operating all 32 valves in the cylinder heads, while variable camshaft adjustment, extra-rigid closed-deck crankcase and a regular production engine-first high-tech, super-low friction cylinder wall coating (known as LDS, for ‘twin wire arc sprayed’) are further innovations.
A single AMG engineer assembles this V8 from start to finish, as shown by the sole signature on the engine plate.
The sole gearbox on offer is an upgraded version of the Mercedes’ 7G-Tronic seven-speed automatic transmission.
It features three shift modes – ‘S’ (Sport), ‘C’ (Comfort) and ‘M’ (Manual) – each with a different shift characteristics and shift speeds – in ‘S’ they’re 30 per cent faster than in ‘C’ while ‘M’ sees a 50 per cent shift-speed increase.
‘M’ has no automatic downshift or upshift, remaining instead in the selected gear.
Aiding the driver are aluminium paddle shifts located on the steering wheel.
Every AMG 63 model also features revised suspension components and high-performance brakes with internally ventilated and perforated discs.
Mercedes says that AMG is now responsible for all chassis, engine, powertrain, suspension, brakes, electronics, aerodynamics, interior and design elements, as well as complete marketing and sales-related autonomy.
Previously, AMG cars were mainly enhanced versions of production Mercedes models.
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