Mercedes-Benz CLK63 AMG 2006 Review

Ahead of them, a Lamborghini. This little convoy through Adelaide suburbs is a moving concours du jour, a random sample of extravaganza that is this year's Classic Rally.

Although our Mercedes-Benz CLK63 AMG has been separated from its badge-mates, it feels at home in this pack.

The tenth Classic Adelaide rally last week attracted hundreds of enthusiasts and 350 exotic cars into the surrounding hills and vales. Like most of those here, we haven't come to race but for the rare chance to sample impressive machinery on closed roads and enjoy the motoring throng.

Mercedes has brought six examples of three AMG models representing a new wave for its tuning specialist — away from large, supercharged V8s and towards naturally aspirated (even larger) V8s.

The E63, CLS63 and CLK63 here all get AMG's new 6.2-litre V8, which replaces the previous supercharged 5.4-litre V8. The most expensive is the sleek four-door CLS63 at $252,300, followed by the E63 sedan at $227,600. By comparison, the CLK63 coupe looks almost affordable at $199,100. All three slot into a range of 17 models that get the AMG treatment, with prices starting at $160,490 for the junior executive C55.

AMG notches up 40 years of tuning Mercedes next year and has already begun celebrating in a sense, with its first completely independent engine — an all-aluminium unit featuring a variable intake manifold and stiff valve train, among other high-tech wizardry.

While power peaks are higher than in the previous V8, it revs higher too and delivers more kilowatts: an extra 28kW for 378kW in the E63 or CLS63, and a generous 84kW for 354kW in the CLK, making the coupe a remarkable 0.6 seconds quicker to 100km/h. Top speeds are electronically limited to 250km/h.

In each case the torque figure is lower than before, but the capacity increase and ability to soar high into the rev range more than compensates. Most of the torque — 500Nm — is on tap from 2000rpm. Next year this engine will arrive in a higher, 386kW state of tune in the S63 and CL63 — the Mercedes flagship limousine and coupe.

One advantage of the lower torque figure is the ability to employ the seven-speed automatic gearbox, ubiquitous elsewhere in its range. Paddle shifters replace steering wheel buttons for manual changes and three shift modes — comfort, sport and manual — progressively increase shift speeds.

All three cars are visually distinguished by subtle AMG body-kitting and more lavish interiors. Adaptive dampers, more powerful brakes and light alloy wheels are standard.

We drove the CLK63 on day one and then swapped into the E63. Both look big and heavy next to most of the rally runners, but amaze with their willingness to corner and ferocious acceleration. The engine delivers a soundtrack that ranges from low thunder to feral as it spins towards 7000rpm. The seven-speed auto is a highlight, changing smoothly and quickly whether in manual or auto mode. Only the over-interventionist nature of the electronic stability control hindered progress when it cut power prematurely in hairpins.

When we did want to stop, the brakes were stronger than expected and complement the powerplant with the right sort of potency. In both cars, the steering was light, Mercedes style, but intuitively accurate.

If we had to pick one car to repeat the trip, it would be the CLK63.

It has less power, narrower rubber and almost as much mass as the E63, but its shorter wheelbase and better balance made it more agile, while its front wheels had an impressive willingness to turn into a corner and stay gripped when there. A proper thoroughbred among thoroughbreds, thanks to the Adelaide rally it's already a classic.