Given such background, undoubtedly, the new generation SL will enter a class of its own. First of all, its sexy styling can blow the oppositions away in the first round of beauty contest. Its basic profile evolves from the 1989 model, featuring similar proportion, trademark grilles and side air vents, but all surfaces and corners are polished to smoother and sleeker. Windscreen and rear window are more steeply raked so that it feels more sporty. The preservation of low shoulder line - as opposed to recent trend - makes it look smarter and cleaner than others, especially facing Lexus SC430. British designer Steve Mattin has done a good job here. 

Like the old car, it looks long but not really so. Measuring at 4535mm, it is just 19mm longer than the Lexus and a massive 225mm shorter than Jaguar XK8. Structurally, biggest change to the chassis is the adoption of SLK-style retractable hard top. Engineers are proud to announce that the electric mechanism takes a world-record 16 seconds to fold the aluminium roof into the boot, some 9 seconds quicker than SLK and 4 sec faster than Lexus SC430. Moreover, the rear window is automatically detached from metal frames and stored independently to take advantage of its curvature in order to save luggage space. As a result, boot volume is a remarkable 265 litres when the roof is down. Roof up, that increase to 290 litres. 

One of the weakness of the old SL was overweight. Therefore the new SL employs aluminium in bonnet, boot lid, front wings and doors, and magnesium inner door shells like its CL cousin. And we have already mentioned the aluminium retractable roof. Better structure and more usage of high-strength steel result in 20% increase of chassis rigidity. Despite of this, the new SL500 tips the scale at 1770kg (or 1845kg according to EU calculating method), some 45kg lighter than the old 500. Aerodynamics is another area of improvement - drag coefficient becomes 0.29 and 0.34 for roof up and down respectively. The old car’s were 0.32 and 0.43. 

While the all-alloy, 3-valve-per-cylinder, 5-litre V8 and the mandatory 5-speed automatic are unchanged, they take advantage of the lighter kerb weight to deliver stronger performance - we are talking about 0-60 in 6.0 seconds and a limited 155mph. If not enough, you can choose the AMG SL55 whose supercharged V8 pumps out 476 horsepower. It should do 0-60 in a supercar-rivaling 4.5 seconds. Nevertheless, as the beauty of SL is always relaxed motoring, I think 306 horsepower is perfectly adequate. The V8 is strong, creamy smooth yet economical for its kind (thanks to automatic cylinder cut-off at light load). Who needs V12 or supercharger ? 

I can’t think of any roadsters or coupes more relaxing to drive. Its engine is so refined, gearshift is so seamless, chassis is so free of NVH, steering is so free of kickback, ride is so compliant, so supple that you might think you are driving a long-wheelbase S-class. Look at the spec. and you’ll know why: suspensions are made of aluminium to reduce unsprung weight; the adoption of active body control (ABC) allows softer setup without ruining handling. The cabin also plays an important role in relaxed motoring - sit on the comfortable and all-adjustable seats with massager and cooling, face the stylish, Alfa-like radical dashboard which is made of far higher quality than any post-1996 Mercedes, press a button and 16 seconds later you are enjoying fresh air and sunshine .... 

But attack the first corner and you’ll know this Mercedes is also a sports car simultaneously. Whenever computer senses hard cornering (or you can switch it manually as well), the active body control enters sports mode, firming up the hydraulic-aided springs at each suspension and limiting body roll in cornering. For example, at certain speed when the old SL rolls 7°, the new car is limited to just 2.5°. The changeover from normal to sport mode is fluent thus you won’t aware the transition point.  

You must also notice 3 other new features that sharpen the handling of SL: 1) the front suspensions has been changed from struts to 4-link to improve camber control, hence front-end grip and agility; 2) like C-class, it employs rack-and-pinion steering instead of the ancient recirculating-ball design. Accompany with a quick steering ratio which takes just 2.6 turns from lock to lock, the steering is now more precise and responsive; 3) the SL introduces the world’s first brake-by-wire system (SBC or Sensontronic Brake Control) which uses electronics to activate brakes rather than today’s hydraulic linkage between pedal and brakes. By doing so, computer can apply different brake pressure to individual wheels, maximizing the performance of ESP yaw control. Until now, ESP can just signal individual wheels to brake more or less frequently but unable to alternate braking force. No wonder the new brakes feel so powerful.  

There are some foolish commentary saying the SL not a real driver’s car because of light steering and incapable of power-oversteer. Forget that. The SL is not designed to take on Ferrari Maranello or Porsche 911. If it were so, it would not have been so comfortable and enjoyable. However, if you let me choose between 911 Carrera and SL500 as my sole car, I think I would choose the latter. It is simply more desirable to own and to enjoy everyday. After all, the new SL’s mission is to continue its domination of the luxurious roadster/coupe market. It does that cleanly, and extend its advantage further. It sends Jaguar XK8/R to the second division, and relegates Lexus SC430 to the third division. Its leadership position is guaranteed until, well, the next generation SL come. 
 

SL55 AMG

What surprise us is how serious AMG this time. Calling SL55 AMG, it would have been logical to assume it use the same 5.5-litre version V8 as the existing CL55, E55, S55 and CLK55 (and if you remember, the last generation C55). 360 horsepower would have been fine for a top SL. However, AMG was not content. It fitted a Japanese-made IHI supercharger into the V-valley in the same way as the smaller V6 of C32, running it at a maximum boost pressure of 0.8 bar. Use your calculator and you will see the engine equals to a 10-litre normally aspirated engine ! unbelievable ... if anyone apart from American love the concept of Muscle Cars, it must be AMG. Since its first 300SE 6.3 - some thirty years ago - it has been producing modern muscle cars. 

You may be slightly disappointed by its 476 hp output, which cannot match a Ferrari 550 V12 (same displacement but no charger). Think about this: the Mercedes mega V8 is somewhat bounded by its basic architecture of single-cam 3-valve-per cylinder. Also, supercharged engines are not good at top end power. On the plus side, it is compact and lightweight for its class. AMG did a very good job in lifting its revability, which sees maximum power occurs at 6,100rpm. However, the strength of the V8 - like most supercharged engines - lies on the torque curve. At just 1500rpm, it pumps out the same torque (369 lbft) as BMW M5 does at peak. At 2000rpm, it overtakes McLaren F1 at its best (479 lbft). From 2650rpm continuously to 4500rpm, it generates the maximum 516 lbft, more than any supercars ever achieved. Only Bentley’s 6.75-litre V8 turbo can better it. 

How fast the SL55 AMG can go ? German magazine Auto Motor und Sport recently tested it against Aston Vanquish, Ferrari 550M, Lambo Murcielago and Porsche GT2 at Italy’s Nardo test track. The result was an astonishing 202 mph, just bettered by the Lamborghini.  

Let me spend some more time on this subject. On the net there were some people suspecting Mercedes supplied AMS a car generating more power to get better result. They simply did not believe the "476hp-only" Mercedes can do more than 200mph. In my opinion, if we can believe a Ferrari F40 reached 196mph out of 478hp, we must believe the Mercedes can do 202mph. Considering the F40 had a drag coefficient of 0.34 while the Mercedes is just 0.29 (the best ever for supercars), if their frontal areas are the same, my calculation tells me the latter can top even 212mph !  

That’s the theory. In reality, Mercedes’ engineers swore they saw 208mph during testing. So why not AMS match that ? because for over 200mph Nardo is not the best place to test top speed. Although the circular test track has banked angle to cancel centrifugal force, it is still no replacement for a pure straight line. That’s why McLaren F1 chose Germany’s Ehra-Leissen test track to record its 240mph top speed. 

Now back to SL55 AMG itself. Excluding engine and performance, the modifications made were rather subtle. This is not a stripped-out performance car. It retains all the creature comfort of the standard SL, including the luxuriously-equipped cabin and retractable roof. As a result, it tips the scale at 1880kg, some 110kg heavier than SL500 because of the strengthened engine, brakes and rear subframe (changed from aluminium to steel). Weight penalty in addition to the use of 5-speed automatic (now with button shift) result in a less impressive 0-60mph time of 4.4 second. Once on rolling, the heavyweight supercar becomes more accelerative. 

Mercedes does not employ its new ceramic brake disc on the car, but using 360mm-diameter disc with 8-piston caliper up front is effective enough to stop the near 2-ton car. Also, it has the SBC brake-by-wire as the standard car. 

It is amazing that the SL55 AMG does not need any suspensions and chassis modifications to cope with its new found performance. The monocoque still feels rock solid at push. The retractable roof doesn’t leak at top speed. The Active Body Control suspensions result in stable and agile cornering. Apart from stronger acceleration force and more tyre noise, you won’t notice you are driving a 200mph supercar. It is so refined that, according to AMS, at 200mph the driver can still search for the switch to activate the massager function of the seats ! before the SL55 AMG, no one could have thought about a supercar so comfortable and easy to drive. Think about how revolutionary Honda NSX was in 1990 against its rawer Ferrari and Porsche rivals and you will understand. Perhaps the AMG’s breakthrough is even bigger than that. 

Any disadvantages ? while the standard SL is not the ultimate driver’s tool for its class, the SL55 AMG is also not a real super sports car. There is no two-edge sword here: for the benefit of refinement, its steering and suspensions filter some road communication that supercars needed. Weight is another problem preventing it from being as agile and throttle adjustable as Ferrari 550 or Porsche 911 Turbo. It can be the King of Autobahn - both in straight line and high-speed bend, but to keen drivers the Maranello is still the ultimate front-engined GT. 
 

SL55 AMG now 500hp

By the way, Autocar magazine tested the car twice and failed to match the performance figures recorded by AMS. The British magazine timed 0-60mph in 4.7 seconds and 0-100mph in 10.3 seconds. Now another suspicion is raised: did Mercedes really give AMS a standard-tuned SL55 for testing? or a car specially tuned to deliver more power?  
 

SL65 AMG

Put them against the clock, the SL65 takes just 4.1 seconds to sprint from rest to 60mph, versus 3.8 seconds the SLR needs. The gap grows wider when arriving 124mph: SL65 takes 12.9 seconds, SLR takes 10.6 seconds. The competition stops when SL65 arrives its electronic regulated top speed of 155mph while SLR continues to cruise to somewhere around 206mph. Theoretically, the SL65's sleeker shape (with a Cd 0.30 versus SLR's 0.374) enables a top speed in excess of 220mph, but nobody would dare to try that - it would be lucky if somebody can see that speed before airborne. The point is, there is always a reason behind the McLaren's poor drag coefficient, and I guess you know why. 

So, instead of trying to compare SL65 AMG with SLR, we had better to concentrate on its own strength - smooth and relatively quiet V12, large and luxurious cockpit, refined ride and that retractable roof. Originally, Mercedes wanted to make SLR the most comfortable supercar, but that was not very successful. Now SL65 AMG could satisfy those who want supercar performance while retaining the luxury of a Mercedes-Benz. And, at the same price as Ferrari 575 Maranello, it seems a bargain too. It can't compete with the Ferrari for handling and feel, but its superior performance will steal many sales from Maranello. 
 

SL facelift and SL63 AMG

Most cars are renewed after 6 and a half years. To Mercedes SL, this is only the Part II of its long life.

New "63" engine brings no actual improvement to performance, but subjectively it is on a new level...