AMG V8 gets blown for big figures

Mercedes-Benz's hot rod haus AMG used this week's Geneva motor show to reveal its new V8 engine to gathered international journalists. Known as the M157, the 5.5-litre V8 is the first of AMG's newest engine family, using twin turbochargers and state-of-the-art direct injection with piezo injectors.

Despite the smaller -- by 747cc -- displacement to the esteemed 6.2-litre V8, the M157 whips the naturally aspirated version. In 'standard' form the biturbo V8 is good for 400kW and 800Nm while an optional Performance Package ups the ante to 420kW/900Nm.

The giant figures place AMG's offering at the top of the luxury performance market tree. The whopping torque in the 400kW version comes at 2000 revs and the Performance Package's 900Nm arrives at 2500 revs.

The biturbo V8 is mated to a new seven-speed transmission with wet start-up clutch (a la SL63 and E 63). AMG attributes the engine's efficiency -- 10.5L/100km -- in part to its new Speedshift transmission.

We'll first see the 5.5-litre V8 in the updated AMG version of CL Coupe, which will be called S-Class Coupe when it arrives in the fourth quarter this year. The new reference follows the naming convention for the CLK-turned-E-Class Coupe/Cabrio, the latter launched this week.

The M157 is built at AMG's facility in Affalterbach. The turbochargers use air-water intercooling with max boost pressure at 1.0 barfor the 400kW version, and 1.3 bar for the Performance Package. Direct petrol injection efficiency is aided by fast acting piezo-electric injectors and spray guided combustion.

The new engine does not replace the naturally aspirated 6.2-litre V8, M156, used in the '63' models, rather, it adds another option to AMG's engine range which also includes the biturbo V12 used in the S-Class.

It's speculated that we can also expect a naturally aspirated version of the 5.5-litre V8 in smaller AMG Benz models such as the C-Class "in the near future".

On smaller options: AMG execs also hinted at the launch that the upcoming A and B-Class platform will be of interest to them with view to an entry in the compact class.

AMG chairman Volker Mornhinweg told the Carsales Network that his company's drive for more distinction means adding more drivetrain options.

"What we will have when it comes to the future is a range of different drivetrains for our product portfolio. That means more than just our 6.3, which is more or less in each of them," he said. "That is how we want to encourage more distinction for and among our brand."

AMG execs also told journalists that hybrid and electric options are being examined for application to models including SUVs. An electric SLS is currently at the disposal of the likes of Mornhinweg for testing, and at the Geneva show 'parent' Mercedes-Benz released details of two powerplant options for its F 800 Study concept: hybrid and hybrid with fuel cell -- the latter offering a range of up to 600km.

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