It's believed the company has aligned the development of the next-generation SL with that of the recently-revealed Mercedes-AMG GT Roadster, which made its debut at this year's Paris motor show.
The collaboration will benefit both sides, as Autocar says it allows AMG to channel resources into more derivatives of the GT, including an even meaner Black Series model that will sit above the GT R - which recently set a steaming hot lap time at the Nurburgring race track.
Above: Mercedes-AMG GT C Roadster
When it launches, likely around 2019, the new SL will adopt the GT's longitudinally-mounted engine layout and rear-mounted transaxle for optimum weight distribution.
The British publication says insiders from the project have confirmed the new SL will also feature an aluminium body structure and carbon-fibre torque tube from the GT, which should help to significantly reduce weight, along with improving performance and economy.
Another weight-saving measure is the switch from a folding aluminium roof – which has been an SL feature for a decade – back to a folding fabric roof.
For the first time since its fourth generation, the new SL could be offered with the option of a soft top or a fixed roof.
Above: Mercedes-AMG SL63
The new SL will likely be offered with the company's new 'M256' 3.0-litre inline-six petrol engine complete with an integrated electric starter motor that allows for a short power boost.
Other units expected to feature are both the 375kW/700Nm 'M176' 4.0-litre twin-turbo V8 seen in the AMG GT S and C63 S, along with the uprated 450kW/800Nm 'M177' version that was launched with the new E63 S – which are said to replace both the 335kW/700Nm 4.7-litre twin-turbo V8 in the current SL500 along with the 430kW/900Nm 5.5-litre twin-turbo V8 in the SL63.
It's unclear whether there will be successors to the SL600 and SL65, which are offered in overseas markets, as their twin-turbocharged V12 engines may not meet ever-tightening emissions regulations.
The higher-output M177 V8 is likely to effectively replace these models, according to an unnamed source familiar to the project.
"From an image standpoint, it would be a great loss to the SL to go without the V12," they said to Autocar. "However, the new V8 provides outstanding performance and economy – and there is still more to come from it in the future."
Stay tuned for more updates on the Mercedes-Benz SL as they come to hand.