Worth the weight?

Mercedes-Benz executive director of hybrid development, Dr Andreas Truckenbrodt, says improving engine efficiency is more important than weight reduction -- in the medium term.

Truckenbrodt commented in the context of MB's future strategy to provide cars that are more sensitive to environmental needs, without unnecessarily harsh imposts on the consumers -- the company's definition of 'sustainable mobility'.

The German marque's expert and head of its new fuel-cell product program (in partnership with Ford and Ballard Power Systems) is in Australia for the Banksia Foundation Awards. The awards recognize environmental excellence. Mercedes-Benz Australia is an event sponsor.

According to Truckenbrodt, the prevailing view at Daimler AG is that too many future prospects for the automotive industry dwell on harm-minimisation for the environment, but don't take into account what is affordable, practical or appealing for the consumer in the here and now.

Truckenbrodt was able to cite an example from the past -- specifically a chapter from Audi's recent (and current) history. In developing the Aluminium Space Frame method of construction for the A8, Audi had certainly reduced the overall weight of the car, but in Truckenbrodt's opinion, the same ends could have been achieved -- and have been achieved – using high-strength and ultra-high-strength steels.

New steel metallurgy is also considerably cheaper than the highly sophisticated ASF system. The advantage with the steel construction method trickles down to the consumer in the form of a reduced purchase price.

"We now have technology that could achieve similar weight in steel, which is much better to make and cheaper to do" says Truckenbrodt.

The Audi story illustrates Truckenbrodt's point that a radical change in construction methods to reduce weight for the sake of fuel efficiency may be rendered redundant within a few years by evolutionary production methodology.

By way of comparison, the Mercedes F 700 concept unveiled at the Frankfurt Motor Show is a road-going, S-Class size car, close to production ready. The 1.8-litre four-cylinder 'DiesOtto' combustion engine, in a hybrid-drive combination with a small electric motor, produces the same output as a conventional 3.5-litre V6 for about the same fuel economy as a Volkswagen Golf Diesel.

Truckenbrodt contends the F 700 demonstrates the way engine technology can move ahead in leaps and bounds, relative to weight reduction measures.

To comply with current safety legislation and still give consumers the bells and whistles, car companies could only reduce weight significantly in the short term by adopting expensive materials such as carbon-fibre and magnesium, to name two. This would reduce weight, but send prices of the cars in question skyrocketing.

Such cars would price themselves out of existence, lending weight to Truckenbrodt's espousal of the MB 'sustainable mobility' philosophy.

Truckenbrodt facetiously declared: "Life would be so nice if the customer wouldn't be there."

Sometimes, it's not enough to give people what they need, it has to be sugar-coated with what they want too.