Mercedes-Benz S350 BlueTEC 2012 review

It's amazing to think a car of this size consumes less fuel than your average hatchback. It seems impossible.

Engine and technology

The heart of the matter is a new direct injection 3.0-litre V6 turbo diesel that pumps out 190kW of power and an impressive 620Nm of torque from a low 1600 revs. That's almost as much torque as the 4.7-litre V8 S500 and it shows in the effortless way the car performs.

In terms of power and torque, the S350 BlueTEC outguns the opposition in the shape of Audi's A8 3.0 TDI and the BMW 730d.

But the S350 is still heavier than both and, as such, consumes more fuel and produces slightly more C02 than its two competitors.

The lighter, aluminium bodied A8 is also quicker from 0 to 100km/h, at 6.1 seconds versus the Benz's 7.1 and the BMW's 7.2 seconds.

The diesel is hooked up to a seven-speed sequential auto and rides on Airmatic air- cushioned suspension.

Driving

We put in a couple of hundred kilometres behind the wheel of the S350 BlueTEC, and found the 3.0-litre V6 is so quiet you wouldn't know you were driving a diesel unless someone told you.

With 620Nm of torque, it gets going quickly and mid-range response is strong, making overtaking is a breeze. But, with close to two tonnes of motor car behind it, throttle response is not immediate — not like the AMG.

At 7.0 litres/100km, the combined fuel consumption represents an 11 percent improvement on the previous engine. The air suspension is a bit floaty for our liking, but switching to sport mode fixes that up.

All in all, we found the car much improved and a more enjoyable drive than before. While it comes with just about every conceivable luxury, it still won't park itself like some cheaper cars.

It will identify if a parking space is suitable and guide the driver into the spot, but you are still required to turn the wheel. The problem is finding an electric motor that is strong enough yet small enough to do the job. Also of interest is reservoir hidden under the spare in the boot.

It contains 27 litres of an additive that is injected into the exhaust process to reduce the amount of nitrogen released into the atmosphere. There's enough to cover 20,000km, so it doesn't need to be topped up between services — but it means you get a smaller, space saver spare wheel.