Mercedes-Benz S 350 BlueTEC Review

2011 Mercedes-Benz S 350 BlueTEC 3.0-litre six-cylinder turbo-diesel, seven-speed automatic gearbox: $213,428 (Manufacturer’s List Price)

2011 Mercedes-Benz S 350 BlueEFFICIENCY 3.5-litre V6 petrol, seven-speed automatic transmission: $220,650 (Manufacturer’s List Price)

Exterior-wise, the updated S-Class remains largely unchanged from the previous model, but it’s under the bonnet where you’ll find most of the major improvements.

Don’t worry about test-driving the S 350 BlueEFFICIENCY petrol version. What you want is the S 350 BlueTEC with 620Nm and 190kW, and you’ll never know you’re driving a diesel.

As a historic comparison, the first diesel passenger car was released by Mercedes-Benz in 1936 as the 260D. It had a displacement of 2.6 litres and developed a whopping 33kW of power. How times have changed.

My colleague and I, would have sworn on the lives of our children, even after clocking up over 100 kilometres, that we were driving the S 350 BlueEFFICIENCY (petrol), until it finally dawned on us both, that the tachometer redlined at 4600rpm instead of the usual 6500rpm – that folks, is the only way that you’ll know you’re driving a diesel once inside the cabin of the S 350 BlueTEC.

Even when accelerating from low down in the rev range, you’ll swear blind that you’re firmly behind the wheel of the petrol powered BlueEFFICIENCY car, as there simply isn’t a single decibel of diesel clatter inside the cabin, once this car is in motion.

Apart from the complete and utter suppression of the usual diesel engine note, the other big selling point for the BlueTEC S-Class is that those 620 Newton-metres start to kick in at 1600rpm and stay on song through to 2400rpm. That’s a point worth considering when you’re moving nearly two tonnes (1995 kilograms) of Mercedes-Benz craftsmanship from point-to-point.

It’s not that the S 350 BlueEFFICIENCY doesn’t get along (at 0-100km/h in 6.9 seconds it’s a fraction quicker than the diesel variant and neck and neck with the current Volkswagen Golf GTI), it’s just that the huge low-down torque of the BlueTEC car is by far the more enjoyable drive.

The S-Class might be the super luxury flagship in the Benz model range, but that doesn’t mean it’s not a driver’s car. The moment you come across the first stretch of windy road, do yourself a favour. Dial up the ‘Sport’ setting for higher revs before each shift point, and then tap the little button with the picture of the damper on it, for more air in the suspension, and less rebound. Mind you, that slightly more aggressive set up will still feel like a comfortable ride, but the car feels more planted and invites a more spirited driving style through those bendy bits.

Power delivery is silky smooth too, and unless you have good reason to stand hard on the throttle, there is very little turbo lag, and it all feels and sounds like petrol power.

Power and torque have increased by 10 and 15 percent respectively over the previous model S-Class diesel, while fuel consumption has fallen by 9.1 percent to a highly commendable 7.0L/100km. Apart from a greater range and fewer fuel stops, buyers of the S 350 BlueTEC will also pay $7,122 less than its petrol powered sibling the S 350 Blue EFFICIENCY, due entirely to the car meeting the 7.0L/100km or below consumption criteria.

That means the S 350 BlueTEC is not only one of the world’s cleanest diesel cars, but it’s also the first EU6-compliant vehicle in Australia, with an emissions output of just 185g/km. That fact alone is extraordinary, especially when you consider that all cars sold in Australia since July 2010 must comply with EU4 emissions. The introduction of EU6 regulations is not planned to come into play until 2014. Not a bad effort for a two-tonne luxury vehicle capable of sprinting from 0-100km/h in 7.1 seconds.

The ‘green’ halo around this car doesn’t stop there either, that’s where the term BlueTEC comes into play. The EU6 badge of honour bestowed upon this car relates to its ability to reduce harmful nitrogen oxide (NOx) emissions. In the S 350 BlueTEC, a synthetic substance called AdBlue (urea solution) is sprayed into the exhaust flow of the car, which introduces ammonia into the exhaust and converts most of these oxides into harmless nitrogen and water droplets.

Of course, owners will have the AdBlue reservoir topped up at every service interval, which in this case, is every 20,000 kilometres.

If you still not sold on BlueTEC diesel power, but you’re a corporate citizen with a conscience, then you probably won’t mind 225kW and 370Nm of BlueEFFICIENCY under your right foot. Not only are power and torque up on the outgoing engine of the same displacement, but fuel consumption has fallen to just 9.0L/100km and CO2 emissions are down to 210g/km.

Although the all-new 60-degree V6 engine is naturally aspirated, its modular design allows for a turbocharger, should that be considered at some later stage. Don’t get me wrong, there’s plenty of punch in the BlueEFFICIENCY car as the 0-100km/h-sprint time suggests, but in-gear acceleration feels far less substantial than the diesel variant. That said the new layout of this engine means extra silky smooth power delivery.

This V6 power plant, like all petrol engines currently used in the Mercedes-Benz stable, is EU5 complaint.

Big brother to the S 350 BlueEFFICIENCY is the S 500 BlueEFFIENCY: a 4.7-litre bi-turbo V8 juggernaut that somehow manages to accelerate from 0-100km/h in five seconds flat, while consuming just 10.5L/100km. It’s an outstanding piece of engineering when you consider its two tonne kerb weight. It’s not so much the increase in power (12 percent) that gets your attention, it’s the massive 32 percent increase in torque over the previous engine from 530Nm to 700Nm that excites.

These various efficiencies are a result of Mercedes-Benz’s in-house 7G-TRONIC PLUS seven-speed auto transmission and the deployment of third-generation direct petrol injection. This is a particularly smooth shifting gearbox that will quickly find its way to seventh gear, in order to achieve the best possible fuel consumption outcome.

Active safety systems have been beefed up across the S-Class range too with the introduction of ‘Active Lane Keeping Assist’ and ‘Active Blind Spot Assist’ as standard fitment.

S-Class also introduces a new traffic management service, which is powered by SUNA in Australia and provides live traffic updates via the car’s GPS system.

Apart from the multiple options packages available throughout the S-Class line up, the new 1200W Bang & Olufsen BeoSound AMG audio system with 15 loudspeakers is also available.

S-Class maintains its position as one of the world’s most luxurious automobiles, while at the same time delivering remarkable fuel efficiency across the entire range.