Accidental Gullwing?

Arguably the most iconic styling motif of Mercedes' long line of sports coupes after the three-pointed star grille, the gullwing door, wasn't in the SLS's planning from day one. That was the bombshell delivered by the Chief Engineer of the Mercedes-Benz SLS AMG program, Dr Frank Emhardt at last week's launch of the three-pointed star's super coupe.

According to Emhardt the one-piece top-hinged doors were not in the car's original design brief, but rather emerged as the clean sheet car advanced from initial concepts to early design feasibility study.

Emhardt said his team had not set out to recreate Benz's legendary 1950s sports car, the 300SL, but rather were tasked with building the ultimate M-B two-door and the first car to be a standalone AMG model.

"It was never the task to relaunch the Gullwing or to look at the 300SL and bring it again. The task was please develop, design and engineer a real, authentic sportscar," Emhardt told the Carsales Network.

"One of the very first settings was the position of the engine. It had to be front mounted -- not middle, not rear or any variant of these but front... because it has a Mercedes star," Emhardt explained.

"Having this fixed point, next requirement was balanced [front:rear] weight ratio and that brought us to the idea to fix the gearbox to the rear; to have this contrasting [balancing] idea to the engine. So a transaxle was born -- to combine rear axle and gearbox and to support rigidity. We wanted a stiff chassis, good values in longitudinal and transverse bending and so on. When we had this set up we started to improve the centre of gravity -- by changing the oil system to dry sump."

It was at this point the 300SL parallels became apparent and the SLS as we know it now took form.

"Our overall team was supported by a few guys from Mercedes -- the styling was done mainly by Mercedes guys [Hans-Dieter Futschik led the team]. Then it occurred within one of the first working meetings that one of stylists came along a said: 'Do you know how close you are to the layout of the former Gullwing'," Emhardt revealed.

We didn't know because we hadn't taken it into consideration before. So we put the layouts [300SL and SLS] one over another and we recognised that if we could incorporate these gullwing doors it would be cool."

Emhardt soon found himself in charge of the trademark assemblies. According to him, the original car's doors were studied closely. Modern safety regulations precluded the adoption of the original car's single plane latching mechanism but lessons were learned from the old cars hinges, and seal arrangement.

"We tried to come from a practical approach. I wanted to have a look at the former construction and design. There are some brilliant ideas in this old door -- the latching mechanism for example -- then the [modern] restrictions came."

Emhardt says his modern doors banish the need of original Gullwing owners to carry round a towel in inclement weather. He promises water, ice and the like won't enter the modern car's cabin when the doors are popped.

Also gone are the original car's leather pull straps. There's a technique to closing the doors if you're a little shorter than average -- aside from craning yourself up out of the seat. No doubt the 'dance' will be part of the car's orientation handover with new owners.

The car's status as a pure sportscar killed off any thoughts of power-operated doors, says Emhardt -- too much extra weight and complexity -- but their design does take into account the needs of owners worldwide. The car can be accessed in a "normal garage" and the overall height when open is still compact enough to cope with Tokyo's double-decker parking stations.

One other advantage of the set up is that the doors can be opened with just 40cm of space on either side of the car. This is substantially less than a normal coupe, says Emhardt.

Unlike the original, the new doors also have fully opening electric windows. The gullwing doors also incorporate window bags for added safety in the event of a side impact or rollover.

It's almost certain that a version of the same airbag arrangement will be used in the upcoming convertible version of the SLS. That car will almost certainly have conventional front hinged doors -- just like the convertible version of the original 300SL.

Also read our full technical rundown and drive impression of the SLS.

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