Mercedes F125 concept (2011) at Frankfurt motor show

Mercedes today unveiled the F125 concept car - a car bearing the three-pointed star's F name to demark it as a tech testbed, and the 125 to mark Merc's 125th anniversary in this four-wheeled business.

It's a hydrogen fuel-cell vehicle, and Merc claims a punchy 1000km (620-mile) range. But the scientists here are proud of the cutting edge lithium sulphur batteries, used to store energy created by the fuel-cell. They can be recharged over an induction plate too.

Hold your horses! Merc admits this is 'two steps ahead', typically a car for say 2025.

'With the F125 we want to show that large, comfortable and safe saloon cars have an excellent future, partly because they are able to operate with no emissions,' said Thomas Weber, R&D boss at Merc. 

Like BMW's i cars, the F125 is a ground-up design, whose lightweight body has been built purposefully to store hydrogen. This is no mere road car, tweaked to suit its new powerplant.

It's made from a mix of materials that sounds more periodic table than production ready: there's carbonfibre, aluminium, composite reinforced plastics and strong, lightweight steels. It's strong enough to host a pair of dramatic gullwing doors, giving easy access to the four seats on offer.

Ha! The new chemical set-up allows a high specific energy density of 350Wh per kilogram, says Merc. That means they can store enough power, and recharge quickly enough, to power a new e4Matic all-wheel drive set-up.

Sounds to us like the Mercedes F125 is a car we'll be hearing plenty more about in the coming years. Just check out the spec sheet:

Length (mm) 4998
Width (mm) 1980
Height (mm) 1430
Wheelbase (mm) 3333
Boot capacity (l) 470
Wheels 7 ½ JX 23
Tyres 245/35 R 23
Peak output of rear motors (kW/hp) each approx. 100/136
Torque of rear motors (Nm) each approx. 200
Peak output of front motors (kW/hp) each approx. 50/68
Torque (front motors) (Nm) each approx. 75
Total sustained output (kW/hp) 170/231
Total peak output (kW/hp) 230/313
Wheel torque (Nm) 3440
Acceleration 0-100 km/h (s) 4.9*
Acceleration 80-120 km/h (s) 3.2*
Top speed (km/h) 220*
Hydrogen consumption (kg/100 km) 0.79**
CO2 comb. (g/km min./max.) 0
Total range acc. to NEDC (km) 1000
Capacity of solid H2 reservoir (kg) approx. 7.5

By Tim Pollard