2018 Mercedes-Benz SL will be AMG-engineered 2+2

As well as receiving a new platform, Mercedes-Benz has also taken the decision to ditch the SL’s folding aluminium roof. For the first time since the fifth generation model ceased production in 2001, the new model, codenamed R232, will flaunt a multi-layer fabric hood similar in construction to that used by the S-Class cabriolet.

Among the engines planned to power the new SL is Mercedes-Benz’s new turbocharged 3.0-litre in-line six-cylinder petrol unit. In the new SL 300 is planned to deliver 365bhp, while added turbocharger boost pressure and other power enhancing measures will see it pumped up to 435bhp for use in the SL 400.

Ranged above them will be the SL 500 running a specially tuned version of AMG’s 4.0-litre V8 with around 455bhp.

Two AMG models are also planned: the SL 63 running a 500bhp-plus version of AMG’s twin-turbocharged 4.0-itre V8 and the range-topping SL 65 with a twin-turbocharged 6.0-litre V12 producing 621bhp.

A Mercedes-Benz spokesman said it was unlikely that Mercedes-AMG’s 43 range would be extended to the SL, given that the current SL 400 uses the same engine as the 43 range, with the same power output. 

Nevertheless, if 43 badging were given to the SL, it’d almost certainly use the engine found in the current SL 400, which is also in the 43-badged AMG line-up.

The current SL has been around in facelifted format since late 2015, so the next-generation SL may still be at least two more years away if it follows the standard timeframe for model cycles.

Currently, the SL 63 produces 577bhp – the same as the E 63 S because they use the same engine in the same state of tune.

As such, it’s likely the entry-level AMG-tuned SL 63 will have the same power output as the E 63, details of which were recently leaked in a document. If that's the case, the SL 63 could have 603bhp and 627lb ft of torque from a twin-turbo 4.0-litre V8 engine.

Both cars also weigh exactly the same – 1845kg - in their current iterations and have a 0-62mph time of 4.1sec with the old 5.5-litre V8 fitted.

The S 63 Cabriolet is faster to 62mph by 0.2sec and still uses the old engine, so it’s safe to assume that the SL’s engine will be in the same state of tune, and that when the S 63 adopts the smaller engine, it will be more powerful than the SL and E-Class AMG-badged cars.

Meanwhile, AMG will continue to produce V12 engines, so it’s a safer bet that the flagship SL 65 will return once again. Another source said the SL was the next in line for development from Mercedes.