AMG welcomes turbo takeover

Mercedes-Benz has handed responsibility for the development of its vee engines to performance division AMG, which in turn has confirmed its last remaining naturally-aspirated V8 engines will soon become extinct.

And AMG boss Tobias Moers has shown no regret at the takeover of forced induction, which will happen when the current SLK cabrio-coupe expires in the second half of this decade, taking with it the 310kW M155 5.5-litre naturally-aspirated V8 engine that powers the SLK 55 AMG.

Perhaps most importantly of all, Moers claims that AMG has overcome the turbo lag issue that is often highlighted by fans of naturally-aspirated engines as a reason they are superior to turbos.

The domination of forced-induction engines will be reflected at parent company Mercedes-Benz, which is now concentrating on the development of a new range of sophisticated inline three, four and six-cylinder petrol engine family.

In Australia the changeover to turbocharging is almost complete, with only the run-out C63 AMG coupe (373kW 6.2) and the order-only G-Wagen G500 (285kW 5.5) V8s coming naturally-aspirated.

The new M177 and M178 4.0-litre biturbo V8s that have been developed by AMG and go into the new C 63 sedan and wagon and GT coupe revealed at the Paris motor show form the basis of both AMG and Benz’s ongoing V8 plans.

The S version of these engines produce 375kW and 650Nm and Moers says their performance is why he sheds no tears for the end of natural-aspiration.

“We achieved our targets,” he said. “When you drive a GT S, C 63 S, whatever, you will recognise we still have the V8 sound.

“We also have a significant increase in fuel efficiency; the C 63 has 30 per cent less fuel consumption than its predecessor, so the car is rated at 8.2L/100km, which is for a V8 in the segment not too bad huh?”

Moers was even happy to have a small dig at the C 63’s rivals from BMW, the M3 and M4, which swapped from naturally-aspirated V8 to twin-turbo inline six-cylinder for the new generation. Those engines produce 317kW and average a claimed 8.3L/100km as autos.

“No-one expected that fuel consumption from a V8 engine,” he said.

“Even in throttle response, which is very important for us, you don’t miss the naturally-aspirated engine.”

Moers explained a new manual mode calibration in both the GT and C 63 produces a linear power output: “It feels like a really sporty, naturally-aspirated engine.

“Even if you brake it down before the corner on racetrack and go bang on the throttle it is instant there.”

Getting the throttle calibration right was “a big challenge” Moers said. He admitted AMG’s engineers had to change their “mindset” to achieve the best response.

“We reduce in the manual driving program the torque, because the torque output is higher than we need. It is all about the driveability of the package.”

Moers said he has no doubt the new AMG V8 has better throttle response than any rival – and he’s driven them.

“We know what we are, today we are benchmark,” he said.

Promisingly, Moers confirmed the fundamental architecture of the M177 and M178 – the M178 in the GT has a dry sump – still had plenty of performance to give.

 “The stress level of that engine is not that big right now. There is more to come. It’s OK. You know what the power figure is today in our V8 engines so you can speculate.”

The highest-output V8 AMG offers in Australia is the 430kW/900Nm M157 5.5-litre biturbo in S 63 AMG.