/ 15 March 2010

No more drab diesels

No More Drab Diesels

My apologies if this week’s normal dose of white knuckle, redline-revving Mail & Guardian motoring reads more like something out the pages of Popular Mechanics.

Mercedes-Benz has added its newest BlueEfficiency diesel engine to the C-Class and E-Class sedans and the launch was more like a science lesson than a car event.

Thankfully we did, at least, get a chance to take both the new diesels for a shakedown, up the big highway towards Polokwane, and what we found was not unsurprising: this engine is a real firecracker.

Merc’s newest oil burner is a 2.0-litre, four cylinder, with two dual stage turbos. It was meant to headline the E-Class Blue-Efficiency launch late last year, but because of technical tweaks to sidestep that perennial South African problem, poor diesel fuel quality, it’s been a few months longer in the pipeline.

In E250 CDi guise it produces 150kW of power and a massive 500Nm of torque. In C220 CDI guise it’s been detuned to 125kW and 400Nm, purely to keep the C-Class in its place at the end of the Mercedes-Benz lineup. Performance and efficiency is almost identical between the two.

A worthwhile by-product of the extra tuning in Germany is that for the first time I can remember in a brand-new high-tech diesel motor, Mercedes-Benz doesn’t restrict you to 50 parts per million (ppm) of sulphur diesel.

In fact, it actually ages you to lob in some greasy 500ppm sulphur diesel every now and again because it acts as a good lubricant for the engine.

Mercedes- Benz says that using 500ppm will create a smokier exhaust, but that’s because the diesel particulate filter will create occasional plumes of smoke from the exhaust pipe anyway, regardless of what type of diesel you use. And on that note the science lesson started.

To attain a smaller carbon footprint and help realise its new holistic approach to overall carbon emissions, Mercedes-Benz exclusively uses dry machining on its newest engine to reduce the consumption of lubricating oils.

The engine block is made from cast iron for extra strength and the crank case and cylinder head from aluminium for minimal frictional resistance.

I think it’s safe to say Mercedes-Benz has gone to town on its first twin-turbo, four-cylinder engine as it’s the world’s most powerful four cylinder diesel engine.

Both the E250 and C220 CDI will accelerate to 100kph in roughly 7.7s, they top out at about 230kph, the average fuel consumption is 5.8-litres per 100km and they produce only 154 to 159g/km CO2. And the heightened performance, as we found on the launch drive, is tangible.

If you’re looking for a little performance, simply ease on to the throttle and the vehicle responds with a meaty surge. And at a highway cruise you have to actively use lacklustre down changes and hard acceleration to bring the consumption figure down.

The normal diesel thrum is quiet and unintrusive. The C220 and E250 CDis are not purely economical machines. They don’t even have six-speed automatic gearboxes, which for me is like a puzzling middle finger to Mercedes-Benz’s BlueEfficiency moniker.

The fuel-efficiency potential with just one extra gear ratio is substantial. These new Mercs are more like Lexus performance hybrids, which supply real-world fun and games when you want them to, but they also look after the Earth … most of the time.

Of course, Mercedes-Benz doesn’t have it all its own way with powerful, efficient diesels. The Jaguar XF diesel S is an equally impressive piece of kit, except it’s still a big sixcylinder unit.

So, Mercedes-Benz seems to be the first to have pulled it off with four cylinders. Interesting divisions are starting to develop in the green race: Volkswagen with its turbo and supercharged petrol engines (and very good diesels), Lexus and Toyota with their hybrids and BMW and Mercedes-Benz with turbo diesels.

It’s tough to say, at this stage, who will win the day, but Mercedes-Benz’s newest diesel engine can rightly grab the headlines just for the minute. It’s also a rather fitting tribute to the 150th anniversary of the birth of diesel inventor Rudolf Diesel.

Pricing
Mercedes Benz C220 CDI Blue- Efficiency sedan: R 387 000
Estate: R 396 000
Mercedes Benz E250 CDI Blue- Efficiency Sedan: R517 000