Mercedes’ route to a greener world

Published Dec 8, 2011

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Mercedes-Benz, just like all other carmaking heavyweights, has a lot to throw at today’s efficiency dilemma and it not only wants to contribute to reduced fuel consumption and CO2 emissions, it’s aiming to save the world by completely eliminating them.

Of course, the road getting to this point, if marketed correctly, can make companies like Mercedes heaps of money and your guess is as good as theirs as to when 100 percent squeaky clean motoring will be a reality. But, business angles aside, the journey has already started and at a press conference held in Pretoria last week, Mercedes outlined three legs for its green trip.

Firstly, Mercedes is working to make its existing vehicles with traditional internal-combustion engines more efficient. It’s a trend that’s sweeping the industry, and along with all the consumer-driven “blue-this” and “green-that” badging, new fuel injection, rolling resistance and aerodynamic technologies are making cars travel further with more power on the same amount of fuel than they did yesterday.

When Mercedes applies efficiency tricks – such as special tyres, lighter materials, disconnectable alternators and aerodynamic underbody covers – to its current range it sticks them with BlueEfficiency badges.

Almost every vehicle it sells now comes with these efficiency packages and the brand’s most economical model – a C220 CDI now drinks 0.4 litres less diesel per 100km than it would without it. In other cases like the more utilitarian G-Class, BlueEfficiency might come across more as marketing hype than actual fuel savings, but efforts are still made under its angular skin to make it a little more environmentally friendly.

BlueEfficiency models are readily available in South Africa.

Step two in Mercedes’ master plan is hybridisation. It’s the same technology made mainstream by the Prius, in that a normal fossil fuel-powered engine works in tandem with a battery-powered electric motor.

Different carmakers pair the two together in different ways, but Merc’s S400 Hybrid (which isn’t sold in our market) cleverly puts electric power straight into an otherwise standard gearbox where it adds supplementary drive. Here it also doubles as a starter motor and a generator to charge the batteries on overrun.

Hybrid technology is also available in some Mercedes heavy trucks and buses, and will likely spread into other passenger vehicles soon. An E300 hybrid has already been shown and is nearing series production.

The third and most difficult leg of Merc’s green journey involves completely emission-free vehicles. Right now Mercedes-Benz makes and sells an entire range of cars that run on either hydrogen fuel cells or battery power alone, but both feature technologies that, as yet, are imperfect.

Hydrogen fuel cell vehicles, such as Merc’s B-Class F-Cell which has just proven itself in an around-the -world journey covering 32 000km, are accepted as one of the most realistic zero-emission vehicles of the future. These cars convert hydrogen into electricity in a chemical reaction that in turn powers an electric motor. The only by-product of the process is water.

The B-Class F-Cell stores up to 3.8kg of hydrogen which gives it a range of around 400km. This sounds like an ideal solution to motoring’s future except that hydrogen production can in itself be a pollutant considering that electricity is required to extract hydrogen from water.

It can also be an expensive process and, in its raw form, hydrogen is a harmful greenhouse gas. It’s also dangerous if handled incorrectly, and in Europe, where real-world experiments with hydrogen power are currently underway, refuelling stations cost three times as much to build as normal petrol stations.

Simpler battery-only powered cars such as A-Class and Vito E-Cells, the Smart Electric Drive, and even a high performance SLS E-Cell are also being used in semi-realistic applications in first-world countries.

The torque provided by these vehicles’ electric motors often make them perform better than their petrol-powered counterparts and with competitive ranges as well, but again electricity is dirty to make, especially in countries like ours which uses coal for the process. Earth elements such as lithium used to create batteries are also limited resources.

Electric cars also face global standards issues such as different countries’ phase outputs, as well as simple recharging plugs’ shapes and sizes, but Merc says it’s working to expedite solutions to these problems. Mercedes South Africa says it is looking to import Smart Electric Drives, but will only offer them to fleets as test units and not to the public. -Star Motoring

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