New engine for SL Roadster family from Merc

The SL Roadster family from Mercedes-Benz has got a heart transplant. The SL 400 comes with a six-cylinder biturbo drive system, according to a company statement. Despite half a litre less displacement the output has risen by 27 hp. There is also 110Nm more torque at its disposal. The price of the SL 400 starts from 97,282.50 euros (for the German market incl. 19pc  VAT). This translates to around Rs 80.28 lakh

Manufactured virtually completely from aluminium, the roadster also sets the standards in the category of luxurious roadsters with its numerous technical innovations. Not forgetting that the SL is entirely suitable for everyday use thanks to its retractable vario-roof.

In contrast to its predecessor, the SL 400 is not fitted with a naturally aspirated engine. Instead it boasts a six-cylinder unit with two turbochargers. Although its displacement has been reduced to three litres, the biturbo drive system develops a high full-load output potential with a charge pressure of 1.8 bar, and facilitates an extremely high torque of 480 Nm at low engine speeds. The efficient six-cylinder meets 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, which Mercedes-Benz was the first car manufacturer to offer in series production. The system pressure is up to 200 bar, the pressure being variably optimised according to the engine's mapping. Piezo injectors enable optimal mixture formation with up to five injections per power stroke. The third-generation direct injection is supplemented by rapid multi-spark ignition, MSI.

The rapid multi-spark ignition can be controlled to vary both the timing of the sparks and the combustion period to suit the relevant operating point. This provides scope for optimising the centre of combustion and improved residual gas compatibility. The result of this is excellent utilisation of the fuel with minimum emissions.