Mercedes-Benz F 125! Concept - 2011 Frankfurt Auto Show

At a preview event held the night before the Frankfurt Auto Show officially opened to the press, Mercedes-Benz unveiled the F 125! (In case you were wondering, the exclamation point after the “125” is all Mercedes, not us.)

Why the bold statement? Two reasons. First, the 125 acknowledges the 125th anniversary of the automobile being invented by Karl Benz. Second, the F 125! has a range of 1000 kilometers (621.4 miles), emissions-free! If you’ve been following alternative fuel trends or Mercedes’ engineering activity, you may have guessed the company’s fuel-cell technology (F-Cell) is at work.

Using hydrogen for its energy source, the environmentally friendly technology is already proven in a B-Class F-Cell that successfully circumnavigated the world—driving 30,000 kilometers through 14 countries and four continents. A Mercedes representative was overheard stating that the F 125! will cover 950 kilometers (590.3 miles) on a full tank of hydrogen alone.

Supplementing the F-Cell is Mercedes’ plug-in hybrid system. The use of a hybrid system enables the concept car to capitalize on range-increasing technologies such as brake regeneration and engine start-stop that couldn’t be used otherwise. With the new lithium-sulfur battery, as opposed to a conventional lithium-ion battery, there’s higher energy density, although power density is about the same. The result is a prototype battery that delivers extended range, or in this case, an extra 50 km (31.1 miles). Adding that to the F-Cell’s 950-km figure gives the F 125! its magical 1000-km range.

As for performance, four electric motors comprise the all-wheel drive e4MATIC system. In total, the F 125! produces 231 continuous horsepower, with a peak output of 313 hp. Mercedes claims the F-Cell plug-in hybrid will accelerate from 0-100 km (0-62 mph)in 4.9 seconds and carry a top speed of 136.7 mph.

Despite its gullwing door configuration, the F 125! has full rear seating and is intended to accommodate four passengers.Mercedes even goes so far as to call it a saloon. The hydrogen tanks are structurally integrated into the floor assembly—instead of clumsy tanks—improving interior space. To compensate for the missing B-pillars, high-strength steel, aluminum and carbon fiber are used to construct a rigid chassis that is also light. The doors use lightweight CFRP and can be opened and closed by hand gestures—a neat, conceptual technology that can also be found in the networked infotainment system with multiple displays (including an autostereoscopic 3D display for the driver).

While only a concept at the moment, the Mercedes-Benz F 125! is a testament to the company’s commitment to F-Cell. Considering it’s a saloon, this might be a taste of what a future S-Class might be.