The launch of a new Mercedes-Benz E-Class is always important, given the influence the car has in the luxury sedan sector.

We'd be hard-pressed to call it exciting though, rapid AMG models excepted. That could be about to change however, as one example of the model's next generation will be very different from the others.

According to CAR magazine (via Motor Authority) one variant of the next Mercedes E-Class would use a carbon-fiber structure, rather than today's steel, to shave as much as 770 pounds off the weight of today's car.

That's a huge difference, and though it won't be applied across the entire E-Class range - presumably due to the relative expense - it will give Mercedes-Benz a high-tech challenger for cars like Audi's e-tron and the BMW i models, both of which use similar lightweight construction.

The E Superlight, as its provisionally known, would also feature a hydrogen fuel-cell powertrain, as seen in the recent F125! concept shown at the 2011 Frankfurt Auto Show.

Mercedes is expected to make around 20,000 units per annum, by 2017. Production would begin in 2015, by which time the carbon E-Class's fuel-cell powertrain should also be catered for by a larger hydrogen infrastructure.

The E Superlight is evidence that carmakers are concentrating on more than just drivetrains in their future vehicles.

The weight of many modern electric cars has been criticized on occasion, with heavy batteries adding a few hundred pounds to even light vehicles like the Smart ForTwo, blunting performance and giving the electric motor more work to do, reducing range.

As the cost of carbon construction falls - several manufacturers have been working on reducing costs and production times - it could become more common, breaking away from its traditional home in no-expense-spared supercars.

The best thing is, reducing weight has benefits regardless of the powertrain - it's just as useful to gasoline minicars as it is for muscle cars or luxury fuel-cell sedans.

We'll be sure to bring you more news on the Mercedes-Benz E Superlight as and when it appears.