Mercedes-Benz SLS AMG E-CellEnlarge Photo
It was a Mercedes-Benz icon before it became a performance flagship. Now it's a messenger for the future: the gullwing's going electric. The SLS AMG Electric Drive electric car is closing in on series production, converting the octane-addicted supercar to fit a greener vision of the future.
Now we've had a brief drive in the South of France, at Circuit Paul Ricard, to confirm that it's the real thing--though Mercedes is still coy about the Electric Drive's future in the U.S.
The Electric Drive first was announced in 2010, and had been vying with an electric version of the Audi R8, the e-tron, to be the first pure electric supercar into series production. Mercedes insists its car will be the first, but it remains unclear whether the R8 e-tron concept will get a second revival--or if it would even be considered a supercar in Swabia.
If it weren't for the electric-green paint on the Electric Drive prototype offered up to Green Car Reports, it would take a moment to distinguish it from the gasoline-burning SLS AMG GT Black Series supercars sliding around a few hundred yards away on a separate loop at the Paul Ricard track. The Electric Drive powertrain sits easily in the signature shape from the past.
The technical transformation? Brutally complex.
Essentially, the SLS AMG is gutted and reformed entirely under the skin to accommodate a massive, 864-cell, 60 kilowatt-hour, 1208-pound lithium-ion battery pack running down the car's spine, along with a quartet of inboard electric motors checking in at about 100 pounds each. (Final curb weight: discreetly unpublished.)
The pack is liquid-cooled and shrouded in carbon fiber for what Mercedes says is "zero-intrusion" protection. The body structure's carbon-fiber too, with body panels hung from an aluminum space frame. It's a buffet of materials and a Ph.D. in materials engineering to integrate them.
Those electric motors handle more than the typical translation of electric power. There's one for each wheel, which enables what Mercedes dubs AMG Torque Dynamics. It's true torque vectoring--each motor can vary power to each wheel--and it's all-wheel drive of the highest order.
The complex of sensors for acceleration and yaw and braking give the marching orders, telling the motors to limit or increase energy, to moderate understeer and oversteer as the need arises and grip goes away.
Add electrohydraulic steering (not pure electric), a racing-style pushrod suspension (developed to accommodate the battery packaging), and carbon-ceramic friction brakes, as well as a layer of stability and traction control that backs up the torque-vectoring system, and the SLS AMG Electric Drive earns some supercar credentials of its own.
Power output is pegged at 740 horsepower, with 738 pound-feet of torque, and the official 0-60 mph estimate is 3.6 seconds, just a scant few tenths off the gas-powered car.