Mercedes SLR McLaren revisted

It harked back to the Gullwing of the 1950s and inspired the separate Mercedes and McLaren supercar approaches today. We look back on the life of the SLR

Mercedes SLR McLaren revisted

The first time I met the SLR McLaren was in 2004. At the time even the inhabitants of Stuttgart, the heart of Mercedes country, were not used to the sight of that car.

Having been a fan of Rudolf Uhlenhaut, the legendary Mercedes engineer who gave us the Gullwing and was said to be able to lap a racetrack quicker than Fangio, I wanted to see whether his famous record, set at below one hour between Munich and Stuttgart, could be beaten today in the spiritual successor to his Gullwing.

Uhlenhaut was hated by his family, and loved by anyone else. He built two special cars for road use which he mostly steered himself. They were known as the 300SLRs, but most people simply called them 'The Uhlenhaut Coupe'. Those extreme machines, built with reliance on superlight and flammable magnesium alloys, were in fact rebodied Formula 1 cars, or equivalents of the car that Sir Stirling Moss took to victory on the Mille Miglia.

Their eight-cylinder inline engines were tilted to one side in order to lower the hood line, had direct mechanical fuel injection (based on the one devised in 1937 for a Daimler-Benz engine which powered the Messerschmitt BF-109 fighter plane) and unusual desmodromic valvegear – as found on some modern Ducati motorbikes.

The driver sat astride a huge triangular bulge in the floor which hugged the gearbox bellhousing underneath, and required some getting used to as the clutch pedal was located separately on the left. The first time since Uhlenhaut's magnificent creation that Mercedes has attempted to build a car really related to F1 is now, with the recently announced AMG Project One hypercar.

My silver SLR from the first production run was waiting for me at a traditional Stuttgart hotel, picked for the height of the ceilings in its underground parking lot. The gullwing doors in those days were not popular, and users were warned not to destroy them.

The following few days when I had the car to myself with no chaperone, I did not bring about a credible crack at Uhlenhaut's record (though, God help me, I tried). Since his time, speed limits and lots of traffic on the highway had emerged. Nevertheless, the car gave me a level of confidence which I profited from later while driving various SLRs repeatedly for different stories.

Chasing records: SLR Coupé

At one point I visited the McLaren premises in Woking where the SLR McLaren was being assembled – rather than produced. It used three different carbonfibre moulding techniques, some taken from the shipbuilding industry, some from aviation.

The resultant survival cell was incredibly stiff, and the engine/gearbox assembly was attached to it via two sturdy longitudinal members sculpted from aluminum. At the very front the engineers placed two carbonfibre cones acting very much like an F1 car's nose cone, as structures capable of absorbing enormous amounts of crash energy.

The very friendly Dr Jurgen Weissinger, who at that time was responsible for the SLR and Maybach programs, told me that the main bone of contention between Stuttgart and Woking lay not in the widely reported dispute with Gordon Murray on technical purity, but rather on the need to make the car as user-friendly and as reliable as a C-class. McLaren was unable to achieve that on its own, and the first prototype delivered to Germany, left outside, was full of water in the morning after a drizzle.

The interior was spartan, and almost totally devoid of today's plastichrome bling, with a small number of buttons and fantastic seats. The lever which controlled the automatic gearbox (in reality a 1000Nm-capable five-speed hydraulic converter automatic box also found in the S-class) had a fliptop metal trigger guard. It was real metal too, cold to the touch, bringing more association with a Messerschmitt fighter's control stick and the trigger it housed.

Press the button under it and the engine woke up with a thunderclap. The supercharged 5.4-litre V8 unit was fed masses of air via a completely straight intake tract from the inside of the Mercedes star on the pointed nose. It produced 626bhp and 780Nm of torque, most of it low down.

The car, weighing just below 1800kg, could accelerate from 0 to 62mph in 3.8 seconds, had a top speed of 209mph. But its most impressive characteristic on paper was the time it took to hit 186mph from standstill: just 28.8 seconds. The specs made intimidating reading.

And on the road, unless at pedestrian speeds, the car was far from docile, and thus displayed an essential supercar trait: it could scare its driver at any time. The brakes were metal-ceramic, very powerful, but difficult to modulate with precision as they were the Sensotronic electro-hydraulic system then introduced on the SL, E-class and the Maybach (Mercedes later turned away from them after a spate of failures and complaints).

But as long as one braked as if on a race track, late and very hard, they worked just fine. The ESP was fully defeatable, and even with the switch in default 'On' mode, was unable (or unwilling) to tame the rear under power in the wet and above third gear. If the driver was brutal and careless with his steering inputs, the suspension would squirm and rebound mercilessly, but smooth inputs rewarded a careful wheelman with stunningly quick progress.

At first I explored the envelope carefully, trying to understand the natural rhythm of this exceptional car. The soundtrack was one of the sensations which assaulted the senses first: a deep, sonorous bellow like that of a back row gospel choir singer, reminiscent only of one car: the original Mercedes SSK.

In a similar manner a wave of bass notes would hit the ears of pedestrians and then Doppler away, leaving a wake of disturbed air. Other pedestrians, who, curious, approached the SLR when it was temporarily stationary, and came too close to one of the side exhausts were subjected to a severe case of trouser leg flapping.

I tried to beat Uhlenhaut's 1955 record – when late for a meeting with Fritz Nallinger he covered 140 miles in around an hour – but it proved futile. Not due to a lack of performance on the part of the car, mind you, but because of people in MPVs doing 50mph while I was hitting 190mph.

The top speed quoted by Mercedes was fully attainable, given some space, and the SLR, known internally as C199, was an outstanding Autobahn cruiser. The rear wing also deployed as an airbrake, very much like on the experimental 300SLR's that Fangio raced. Close to top speed the car felt brilliantly composed, with none of the skittishness you would experience in lesser automobiles.

Some have claimed that the slushbox was too slow to change gear and thus the SLR should not be classified as a sports car. Not so! The Ferrari and Lamborghini school of needlessly fast gearchanges would have people wildly shifting instead of actually going fast. In the SLR, because of the massive, non-turbocharged grunt, you could stay in a higher gear, keep your line neat and it would effortlessly pull you onto the straight. Staccato gearchanges do not mean you are going faster, the lap time does.

The only major downsides to the SLR were that a) the navigation system was useless, and b) the car wasn't really mine.

Losing the roof: SLR Roadster

At the launch I again met the Dr. Weissinger, who told me that with the roof tucked away they tried and failed to get air to buffet inside the cockpit at an unrestricted 217mph. I was skeptical, and obviously had to test the veracity of that statement. The launch route was not conducive to that, alas.

Creeping along the Rhine, I decided to try to get the lowest fuel consumption possible. The technique to get the SLR to sip fuel is this: feather the throttle, go to manual on the gearbox and keep it in the tallest possible gear. It won't downshift unless the revs drop critically low. I managed to get about 24 mpg.

The next section was faster and more flowing, and I found to my pleasure that the Roadster had sacrificed absolutely none of the structural rigidity of the coupe. It was slightly heavier, and therefore slower to 62mph by one tenth of a second – hardly a big trade-off.

Weissinger's team wanted to build the best soft-top available. Already the body of the SLR was well suited to that task as the two occupants sat very low down, and the waistline was high. The roof was made of a special technical fabric, somewhat like GoreTex, and the leading edge, which bolted automatically onto the windshield frame, was actually a big chunk of billet aluminium with the fabric securely bonded to it. Therefore at high speed the front of the roof would never deform, bubble or wiggle in the slipstream – unlike its Lamborghini Murcielago hypercar rival.

And so the plan was to hit over 200mph with the roof down to feel the buffeting in the cockpit for myself. But all the highways left on the route for the day were restricted and congested.

While all sane journalists turned towards downtown Frankfurt and the safety of the overnight hotel, I turned towards Frankfurter Kreuz, and there onwards to Giessen. I remembered that the Autobahn from Giessen back to Frankfurt was derestricted. Not much later I learned I was right, there wasn't much traffic, but the highway had only two lanes in each direction. Oh well.

With the top down, I pushed the big hammerhead shark to over 200mph. My colleague was trying to get a handheld GPS unit to verify the speed, but the machine became confused on the far side of 170mph. We hit 205mph indicated, and while it was impossible to talk, the cockpit was fire from the usual whirlwind. Most impressive and learned all in the name of consumer advice.

The best one: 722

By far the most focused and simply the best variant of the SLR and yet a car so misunderstood in period. It was so-named to commemorate Sir Stirling Moss's Mille Miglia victory in the iconic 300 SLR bearing the 722 number.

The car looked sharp, especially in the immaculate gunmetal grey – its launch colour. The 722 was lower, the suspension stiffer, aero aids improved, and the engine was now producing 650bhp plus 820Nm of torque. It was also lighter, and could reach 186mph from a standstill in 28 seconds flat.

It had been perfected in many small ways and the result was astonishing. A huge drop in understeer, an incisiveness that had been missing previously. The Emirates are not really a corner-rich country, but we managed to locate some in a mountainous corner of the country. The car felt solid, newly focused, as if the thin layer of fat had been neatly trimmed with a razor.

The 722 remains to this day on my list of 20 best cars I have driven because it so elegantly married the mile-muncher character of the original SLR with a racing spirit.

SLR in the market today

At launch, many prominent car magazines described the SLR McLaren as a ‘flawed supercar’.

With the benefit of hindsight I can safely say that my colleagues had had expectations that no car could possibly fulfill, and they concentrated excessively on the myth of how Mercedes had ‘spoiled’ the genius ideas of McLaren (which was making no other road cars at the time).

They criticised the slow gearbox and the ‘banality’ of some Mercedes parts. Fortunately for the car, none of those journalists ever bought one, and the buyers did not share their views.

The exceptional reliability of the SLR gave it repeat customers, with numerous individuals owning more than one unit.

The current market value reflects the fact that the car's perceived shortcomings are no longer remembered, and that cars change hands because buyers are sure they are well served by a vehicle which can be driven every day like a humble 911. Tired cars with insufficient provenance are worth in excess of US$250,000, with pristine examples accompanied by full history and low mileage being offered at more than US$400,000.

Considering the performance of the car and today's values of Porsches and Ferraris, this might still be considered a bargain.

As an aside, you can easily spot a SLR in front of Blenheim Palace – the location of a sequence in the Spectre Bond movie – close to which Daniel Craig parks his DB10, among ranks of other supercars.

Images courtesy of Piotr R. Frankowski and Dieter Rebmann

You can view Mercedes SLR McLarens listed for sale here..

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