Combustion engines obsolete by 2050

* Mercedes predicts demise of petrol/diesel engine * 'Broad mix' of drive systems by 2050 * SLS E-cell could be put into production...

Combustion engines obsolete by 2050

Mercedes-Benz believes that cars powered solely by petrol and diesel engines will have virtually ceased to exist within 40 years.

By 2050, electric and plug-in hybrid cars will take care of most of our personal transport needs with hydrogen fuel-cell vehicles also playing a significant role, says the company that is about to celebrate the 125th anniversary of the invention of the car by its founder, Karl Benz. Pure petrol and diesel models will account for a mere 5% of the market.

Dr Volker Storkmann, who heads a team developing electric cars for Mercedes and Smart, calls it 'the second invention of the automobile'.

He says: 'In future there will not be just a single drive technology but a broad mix of different drive systems.'

Mercedes has a hybrid version of the S-Class in some markets, but the move towards electrification will start to gather pace when an all-electric Smart goes on sale in 2012, five years after field trials began in London with prototypes the previous-generation model.

More in the pipeline
However, the company has plenty more things up its corporate sleeve. Five hundred all-electric versions of the five-door A-Class have been leased to customers in several European countries led by Germany, France and the Netherlands to help gather data, and 70 B-Class cars powered by hydrogen fuel cells will be put out to families in California by 2012, part of a batch of 200 that will be made available.

Mercedes even has an electric version of the SLS gull-wing supercar under development.

Thanks to their sandwich floor construction, the A- and B-Class are well suited to electrification, since their large, heavy battery packs can be housed between the two floors, benefiting safety and weight distribution.

Mercedes has developed modular batteries and motors which can be used in anything from a Smart to a van, and are suitable for hybrid, range-extender or hydrogen fuel-cell cars.

The A-Class E-cell all-electric car has a range of up to 125 miles on a full charge, develops 95bhp and is capable of around 95mph.

Crucially, because the batteries are beneath the floor they don't eat into passenger or luggage space. The car feels showroom-ready, with the kind of smooth, seamless acceleration (there's 210lb ft of uninterrupted torque from standstill) that even the best petrol or diesel automatic mid-sized cars can't match, so in a real-world cityscape it's brisker and more pleasant to drive.

'The focus now is to reduce the cost of the batteries, which can be 40-50% of the cost of the car,' says Storkmann, 'but it shows that electric mobility is possible even today.'

Mercedes also considers the hydrogen B-Class F-cell to be 'finished and suitable for everyday use', although there are challenges beyond making it work to be overcome, not least cost and the lack of a refuelling infrastructure.

The first of those will be helped in the next few years by reducing the amount of platinum in the car's 'engine', the fuel stack that turns hydrogen and oxygen into electricity and water vapour, the only waste product.

The hydrogen B-Class isn't as refined as the battery-powered A-Class noise levels and overall smoothness could be improved but it has the advantages of a much greater range (250 miles) and can be refuelled in three minutes, whereas the A-Class takes eight hours to recharge even from a high-power (400-volt) socket.

Both cars develop the same torque, but the hydrogen car has a third more power 130bhp.

Perhaps it's the all-electric SLS E-cell which most proves that Mercedes is deadly serious about turning pure petrol and diesel cars into things of the past, however.

It is only 0.2 seconds slower to 60mph than the V8 petrol version, despite weighing 300kg more and the engineers are confident they can further reduce the weight, which might stretch its range beyond the current max of 100 miles.

Four electric motors, one close to each wheel, deliver close to 300bhp and more than 440lb ft of torque in 'comfort' mode and well over 500bhp with a little more than 600lb ft at the touch of the 'sport' button.

This isn't fantasy stuff, either: the car exists, we've driven it and all these gadgets really work. It feels strange being hurled forward at such a rapid rate with no more than a few whirrs and clicks as accompaniment.

Each electric motor has its own gearbox, housed in two casings one front and one rear. The gearboxes are necessary because the motors will spin to only 12,000rpm, so some means of stretching the car's legs is necessary. At the moment it is artificially limited to a maximum speed of 156mph, but another 4mph is technically possible.

Officially, production has yet to be sanctioned Mercedes merely talks about 'the prospect of a small-series production run' but as a statement of intent, and a response to the electric sports cars being planned by Audi and BMW, it would be hard for Mercedes to resist, though the technology would ensure a substantial price.