Mercedes-Benz has announced a new engine for the SL roadster, a 3.0-liter biturbo V6 unit that replaces the naturally-aspirated 3.5-liter V6 sold as the SL 350. The new model gets the SL 400 moniker to highlight the increase in power, as the new engine produces 27 hp and 110 Nm (81 lb-ft) more than the outgoing unit, rated at 329 hp (333PS) and 480 Nm (354 lb-ft) of torque.

Thanks to the biturbo system with a charge pressure of 1.8 bar, peak torque is available between 1,600 and 4,000 rpm. With the new engine mated to a seven-speed automatic transmission, the SL sprints from 0 to 100 km/h (62 mph) in 5.2 seconds, 0.7 seconds faster than the SL 350. Top speed remains electronically-limited at 250 km/h (155 mph).

Combined fuel consumption is also improved: the SL 400 averages 7.3 l/100 km (32.3 mpg US), compared to 7.5 l/100 km (31.3 mpg US) in the SL 350. CO2 emissions are 172 g/km, with the engine meeting the EU6 emissions standard.

Like all BlueDIRECT petrol engines the biturbo engine in the new SL 400 also works with a direct injection system with spray-guided combustion with a system pressure of up to 200 bar.

The Mercedes-Benz SL 400 is fitted as standard with the Frontbass audio system which is said to provide concert hall acoustics even with the top down. Also standard is the Magic Vision Control wipe/wash system that takes water from the wiper blade to the windscreen as required and irrespective of the direction of wipe.

The new Mercedes-Benz SL 400 starts from €97,282.50 ($133,375) in Germany, including 19 percent VAT.

Features an aggressive body kit

Following a preview earlier this year, JMS and Piecha have unveiled their Avalange GT-R body kit for the Mercedes SL.

Starting up front, the convertible has been equipped with a new front bumper (€3570) that features "air blades" and integrated LED daytime running lights. The car also has a 25mm reduced ride height (€499) and aerodynamic side skirts (€2090) which can be equipped with optional LED lights (€298).

Moving further back, there's a ventilated rear bumper (€2975) with an aggressive diffuser which is flanked by trapezoidal exhaust tips (€573). There's also a decklid spoiler (€785) which promises to help keep the car planted at speed.

Customers can also order 20-inch alloy wheels (€3190) and a 12-piece fin set in high gloss black, shadow graphite matte and "Galvanosilber."

Arriving next year as 2017MY

Our spies have sent us the first batch of images depicting the Mercedes-Benz SL facelift.

Revealed towards the end of 2011, the SL (R231) will get a facelift sometime next year which judging by the camouflage fitted onto this prototype will come with substantial changes at the front. The grille, bumper and headlights are covered up in camouflage and there's also some disguise at the base of the hood.

It seems the top will also go through cosmetic surgery while the rear end appears untouched but upon closer inspection you will notice the design is covered in body-colored camouflage, hence the duct tape on the bumper’s sides and the cutout for the parking sensors.

At the moment it's not known whether the facelifted SL will come with changes in the engine department. As a reminder, Mercedes-Benz introduced an entry-level SL400 variant last year with a V6 3.0-liter twin-turbo engine outputting 329 bhp (245 kW) and 479 Nm (354 lb-ft) channeled to the wheels through a 7-speed automatic gearbox.

Expect the Mercedes-Benz SL facelift to be unveiled next year as a 2017MY.