BlueTEC. Heard of it? The new badge describes Merc’s latest step in its BlueEfficiency efforts to save the polar bears, and is a badge you’ll only see on diesel Mercs.
BlueEfficiency, as you may know, is the banner the German carmaker uses to describe various technologies being implemented across different ranges to improve fuel consumption and lower emission levels – either through lighter and brighter engines or slipperier and more aerodynamic bodies.
The diesel-engined S350 BlueTEC is the first Mercedes to get the new badge. The car replaces the S350 CDI, which ran a 3-litre turbodiesel and was detuned to run on regular 500ppm diesel.
The new technology now means that the same V6 engine from the CDI is powered up from 155kW/540Nm to 190kW/620Nm, but only low-sulphur 50ppm diesel is allowed in that 83-litre tank. I’ve found that this cleaner diesel is now available at most garages in Gauteng’s suburbs, but it is a little more expensive than regular diesel (not that an S-Class buyer would notice), and it may be scarce in smaller towns.
Combined with cleaner diesel is a diesel particulate filter and catalytic filter, but the real BlueTEC innovation is a special exhaust gas additive called AdBlue.
The AdBlue liquid is a non-flammable aqueous urea solution, which when injected into the exhaust flow releases ammonia which converts up to 80 percent of harmful nitrogen oxides into environment friendly nitrogen and water. Call it Merc’s way of converting diesel into butterflies.
This all happens from a 25.7-litre AdBlue tank which sits under the luggage compartment floor. I tried looking for it, but it’s actually under the spare tyre and not visible by just raising the mat in the boot. Not that you’d ever need to find the AdBlue tank as its capacity is designed to last around 20 000km, which means it will be topped up at every service by the workshop.
It’s also a warning that when replacing a rear silencer you make sure to do it through a dealership – I’m not so sure your corner exhaust centre will have the correct part, let alone know about the technology.
The benefits seem to be very real though. According to Merc the S350 BlueTEC already complies with EU6 emission levels due for introduction only in 2014, with C02 levels down from 199g/km in the previous S350 CDI to 177.
Consumption, from 7.6l/100km in the S350 CDI, is claimed to be down to 6.8. Our week long test, with a fair amount of urban and freeway driving, returned a much higher 11.9l/100km. That would seem fair for a barge this size if it wasn’t for the fact that a BMW 730d we tested averaged less than nine litres.
Mercedes also claims that with the increase in power the BlueTEC will hit 100km/h from standstill in 7.1 seconds, before topping out at 250km/h. However, the best 0-100km/h time we managed was 8.3 seconds.
Living with an S-Class almost seems to isolate you from the world. You start listening to Classic FM while cruising to work, feel just about vacuum sealed inside your own plush little world, and guide rather than drive the saloon along your daily route.
The 7-speed box generally keeps things boiling at around the 2 000rpm mark, demanding a gear change then unless you really foot it. And footing it just seems such an uncultured thing to do, providing no real attraction when you do, so you feather the throttle and tap your fingers on the wooden steering to Bach or Beethoven.
Until the rain gods have a domestic dispute, that is. The heavens opened in a Katrina kind of way on one of the test days and even the fastest wiper setting was like Vaseline rubbed on the windscreen. Which is not unusual, except that the Pre Safe and Active Blind Spot Assist systems gave up the ghost – I got disconcerting warnings on the driver’s display warning that they were unavailable.
I can understand that the sensors can’t see in heavy rain, but the warnings persisted for a short while after the rain stopped, and to be honest it’s exactly that kind of weather when I need all the systems the most.
Quite cool though is the Active Lane Keeping Assist system, which I learned about the hard way when accidently crossing the yellow line and finding the car auto correct for me. I thought I was imagining things. Which then obviously made me cross the yellow line a dozen more times that week, just to marvel at the S350 braking the rear wheel on the opposite side of the line to get it back in its lane. Amazing stuff.
VERDICT:
Most S-Class buyers will never need more power than on offer in the S350. The BlueTEC part does its bit in the background, but really has no impact whatsoever on the luxurious feel of the S-Class. Is it really all that planet-saving though? Especially when you consider that competitors like the BMW 730d sip far less fuel, and without resorting to any fancy green or blue badging. -Star Motoring