The development of SLR was never smooth, because the requirements of Stuttgart conflicted with the vision of Gordon Murray from time to time - the former wanted more luxury and quality, the latter wanted lightness and pureness. Of course, the client always wins, and the kerb weight of SLR increased from the original target of 1400kg to the production car’s 1693kg.  

And this is already a car employing all-carbon fiber body and monocoque chassis ! in the press release, Mercedes used thousands of words to describe the advanced construction of the chassis, such as the world’s first carbon fiber crash structure, new production method and blah blah blah. Excuse me, if I build a supercar weighing 300kg more than rivals and only 187kg lighter than a standard SL55 AMG (which has retractable roof, remember), I will be shamed to mention the word "carbon-fiber". No wonder Gordon Murray did not appear in the introduction of SLR. This is definitely not his best car. 

Anyway, the concept of SLR is inspiring. Gordon Murray shares Ferrari’s opinion that a good handling FR car must have a slight rear-biased weight distribution to sharpen steering and improve traction. Therefore he put the engine far back in the chassis, not just behind the front axle, but the whole engine is behind the front wheels. If you don’t believe, open the bonnet and you will see the front half of the engine compartment contains just the suspensions and a big air filter. The compact AMG 5.5-litre supercharged V8 occupies the rear half. Murray could choose a bigger twin-turbo V12 from AMG, but he needs the compact size of the V8 to achieve the desired balance. Besides, it weighs just 232kg, far lighter than the twin-turbo V12 and just 7kg heavier than Ferrari Enzo’s naturally-aspirated V12. The SLR can therefore achieve 49:51 weight distribution front-to-rear. 

From outside, you can also see its attention to balance. The car has a very long engine compartment while the small passenger compartment sits just in front of the rear wheels. The basic design follows that of the Vision SLR, but the profile is evolved to wedge shape to reduce aerodynamic lift at the rear. However, the stunning F1 nose is retained to remind you it is a McLaren-Mercedes. 

Does it look handsome? it might not be as beautiful as Murcielago and Zonda, but it is undoubtedly a good looking GT. Prettier than Enzo, more striking than Carrera GT.  

To allow the SLR to run stable at 200mph, Gordon Murray sacrificed drag for downforce and cooling. As a result, drag coefficient has been increased from the concept car’s 0.29 to the production car’s 0.374. To allow the adoption of flat underbody and diffusers, Murray had to ask AMG to develop a side exhaust system. Catalytic converters and mufflers locate at east and west of the V8 and exhaust gas flows out directly at the exhaust pipes behind front wheels. Shark-like side air vents are opened to help cooling the cats and mufflers.  

The engine is modified from SL55AMG’s. Firstly, the engine is converted to dry-sump to lower its center of gravity as well as to ensure effective lubrication under high cornering force. Secondly, a slightly faster-rotating IHI Lysholm-type supercharger lifts boost pressure from 0.8 to 0.9 bar. Then there are other enhancement to intake, exhaust and cooling, lower friction and lighter moving parts etc. The result is 626 horsepower at 6500rpm - amusingly, just 1 horsepower short of McLaren’s last car. This put it above Porsche Carrera GT (612hp) and Zonda (555hp), although still some way behind Enzo (660hp). 

By the standard of supercharged engines, this one is very efficient indeed. It pumps out 115 horsepower per litre, compare with Ford GT’s 93hp / litre. It also loves to rev. Despite of the 3-valve head and lack of variable valve timing, redline is set at 7000rpm, compare with Ford GT’s 6500rpm. Of course, it shares the common strength of all supercharged engines: torquey. From 3250 rpm all the way to 5000rpm, it delivers 575 lbft of torque, beating all its rivals. At just 1500rpm, it already generates more torque than Porsche Carrera GT can manage at any rev ! 

No wonder a 5-speed automatic transmission is deemed to be sufficient. From the beginning, Mercedes insisted the car must use automatic gearbox to deliver an ease of control unfound in other supercars. There were hopes that its new 7G-Tronic 7-speed automatic could be available, but unfortunately in the mean time it is not strong enough to cope with the SLR engine, so the old 5-speeder is used instead. 

To reduce vibration, the engine and transmission are not bolted directly to the carbon-fiber monocoque. Instead, they are mounted on an aluminum cradle (which also mounts the front suspensions). The cradle is then bolted to the monocoque. At the rear, suspensions and rear axle are bolted to the integral metal link points on the monocoque. All suspensions are by forged aluminum double wishbones. Surprisingly, there is no adaptive damping and Active Body Control. It just employs conventional springs and dampers. 

On the Road 

The SLR has butterfly doors like Ferrari Enzo. Despite of its tremendous weight, the cockpit is rather cramped. Headroom and legroom are tight if you are over 6ft 2in. Steering wheel is close to driver. Nevertheless, the red leather-clad cabin looks luxurious and is loaded with equipment cannot be dreamed in other supercars, such as air conditioning with automatic climate control, CD changer, Bose sound system, mobile phone, satellite navigation and telescopic steering wheel. Even the tailor-made, carbon-fiber-backed leather seats are adjustable electrically back and forth. 

Start the V8, shift the automatic gearbox to "Drive" and drive it slowly, the deep, rubble-bumble exhaust note sounds great ! throttle response of the V8 is instantaneous. Press the throttle, the car immediately surges ahead. Thanks to the rich bottom to mid-range torque, acceleration is astonishing. According to Mercedes, 0-100kph (62mph) takes 3.8 sec, 0-200kph (124mph) takes 10.6 sec, 0-300kph (186mph) takes 28.8 sec and the car tops 207mph. It’s a match with the fastest ever Porsche and runs very close to the fastest ever Ferrari, yet the gearbox is still in the "Drive" position ! like all fast Mercedes, the SLR McLaren is easy to drive fast. 

But it is not the most refined. There is a great deal of tire noise and suspension noise transmitted to the cabin, blame to the rear suspensions which are mounted directly to the carbon-fiber monocoque, and they are just inches behind the driver. The ride is also less absorbing than expected. It deals worst with primary bumps thus is not very suitable for B-roads. As speed rise, the damping improves noticeably, offering a stable ride. Adaptive damping - as fitted to Enzo - could be an answer, but strangely and ridiculously, this 1693kg machine does not have it. 

The steering is a similar story. On irregular surfaces the weight and feedback is inconsistent and even nervous. This is a bad news if you want to attack B-roads. Even on smooth surfaces it is not one of the best steering systems on the market, because it feels vague and light at the straight-ahead position. The weighting improves once you move towards the extreme, and the 2.2-turn ratio is quick and direct, but it is never full of feel. 

Nevertheless, the handling of SLR is immensely stable and well mannered. Its wide tracks, strong grip and rigid chassis help it to corner rock-steadily. The FR chassis balances beautifully. Unlike other mid-engined supercars, its handling bias towards understeer when it approach limit. Of course, you can push the tail out easily by using the tremendous torque, but the ESP stability control - set to be pretty tolerable in normal condition - will dig in smoothly. 

Unfortunately, the brakes do not match the handling. On paper, ceramic discs, 370mm front with 8-piston calliper, 360mm rear with 4-piston calliper seems to be a winning formula. Yes, they are really powerful and fade-free under hard use, but the pedal is unusually difficult to modulate. All is blame to the complicated, brake-by-wire, Mercedes Sensotronic Brake Control. SBC has been used in the SL-class quite well, but in the higher performance SLR and mates with ceramic brake discs it is simply disastrous. As there is no hydraulic linkage between brakes and pedal, as it measures only the pedal travel to determine brake force, the pedal feel is always soft and the driver cannot feel the exact state of braking. As a result, you can easily overbrake or underbrake the car. If you want to stop the car hard, that’s fine, just press the pedal to the bottom. If you want to slow down the car into a corner, you will find it is very difficult to apply the braking smoothly, blame to the lack of pedal feel and the poor calibration of the system. 

I can’t believe Gordon Murray needed SBC. A conventional hydraulic braking system is just fine and save weight, why bother with an unnecessary technology? he must thought so. Unfortunately, the German might think otherwise. They want to show more technologies to their customers - seems that ABS, ESP, DSC and "air brake" are not enough to them.  

No wonder Murray disappeared from the public since the car was launched. I can understand his frustration. His McLaren F1 was so successful because he was given full freedom to design and engineer the car. In contrast, the German Big Brothers had too much say in the SLR project, even in the fields they don’t understand. 

Mercedes SLR McLaren is the most exotic front-engined GT ever produced. Its performance matches other supercars. Its handling is sharp and capable. Its practicality exceeds everyone else - which supercar offer a well-equipped cabin, automatic transmission, a lot of electronic driving aids and a boot big enough for 2 golf bags? unfortunately, it has some serious flaws in braking and steering. Besides, it could do better in ride and NVH suppression to match its otherwise comfortable manner. Now let’s see whether Ferrari can move the game on.