The move to the aluminum-heavy MSA platform unlocks the weight savings. If company honchos decide to market the R232 SL under the AMG brand, rear seats will create space between the SL and the AMG GT, in addition to making the SL more practical. A stretched wheelbase is expected to make more room in the cabin than one finds in the S-Class Coupe. The soft top, not seen on an SL since 2001, will open up space behind the front seats. "Practical" doesn't mean "softer," however. Front/mid-engine placement, and lower positioning for the engine and transmission mean a lower center of gravity and higher dynamic capability, while active stabilizer bars, all-wheel drive, and rear wheel steering help extract the last tenth.
The heavy wedge shape employed to swallow a hardtop will be no more, now that a thin soft top stows under the rear deck. Descriptions promise a "butch, almost mean-looking sports car" with large intakes and plenty of vents, aggressive headlights, and integrated, horizontal taillights.
There appears to be some debate about engine options. Automobile says there'll be four choices, starting with a 435-hp, 3.0-liter inline-six in the SL 43. Then would come 4.0-liter, twin-turbo V8 in the 522-hp SL 53, a the same TT V8 in the 612-hp SL 63. Those three trims would get 48-volt, 20-hp mild hybrid systems. The SL 73 plug-in hybrid tops the range with a 612-hp V8 and a 204-hp e-motor, a powerplant derived from the AMG Project One that could also head to the S-Class sedan, the GLS, and the AMG GT/4.
A report from Autocar last April outlined a much more traditional engine approach, and model naming retained under the Mercedes umbrella. That article said there'd be an 365-hp SL 300, and a 435-hp SL 400 using the same 3.0-liter, inline-six, then would come an SL 500 with 455-hp from the 4.0-liter TT V8. The two AMG versions would be the 603-hp SL 63 and SL 65, that latter with a 6.0-liter V12 and 621 hp. Autocar said a Mercedes spokesman dismissed the likelihood of an SL 43, since the SL 400 uses the same engine at the AMG 43 series.
The truth will come out soon. But what's clear already is that the coming SL will be, in the words of a Mercedes insider, "a vastly different proposition to today's model."