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—Seville, Spain

The F700 was the crown jewel in Mercedes’ “Road to Tomorrow” fashion show of cars at last September’s Frankfurt Motor Show. Following on the wheels of the F600 Hygenius research car at the 2005 Tokyo show, the F700 carries on the F tradition of shedding light on future technologies that could be readily adopted by all companies within a few years. It also continues a sea life theme.

The F600 styling was influenced by the glorious boxfish found mainly in mid-latitude warm waters, and the F700 exterior design by the Mercedes advanced design studio in Irvine, California, takes its cues from the brainy dolphin. And there’s a lot of brain behind this polarizing science-mobile.
Mercedes had twenty-one different vehicles for us to drive, or, in the case of the F600 and F700, be driven in, plus seven models that we’ll be writing about soon but were barred from driving for the moment. Sifting through all of the assembled treats, however, left us with three big stars for our current focus: the F700 research car, an S-class fitted with Pre-Scan suspension, and another S-class powered by the 1.8-liter DiesOtto engine. We drove the latter two cars on a closed circuit, and that allowed us to better understand the two chief technological highlights of the F700.

First, we know it’s a tall order, but don’t focus on the F700’s “Aqua Dynamic” design too much. If any of this wild styling makes it onto future cars, it will just be isolated parts of the design. This is not the 2012 S-class, okay?

For our ride experience at the circuit outside of Seville, the Mercedes team had already set up the Reverse Seat at the right rear to have us facing backwards, which put our right ear pleasantly close to the voice of chief engineer for the F700, Jürgen Hirsch. No sooner had we entered the circuit from the pit lane for our three ride-lecture laps than engineer Hirsch divulged to us, “In the rear-facing position we find that around 60 percent of passengers are okay, but the other 40 percent can get a little ill.” We did not get ill, but those percentages—plus the fact that the right front seat is rendered unusable by this flourish—make it safe to say that this particular seat solution will not be offered on a Mercedes mass-production car soon. Watching the Reverse Seat do its movements was nonetheless extremely cool stuff, and it was comfy gazing rearward with our feet up and watching the twenty-inch 3D display that rises out of the back shelf.

Sitting on the stretched S-class chassis, the F700 is 204 inches long, or just one inch less than the current long-wheelbase S-class. At the same time, however, the F700 wheelbase of 135.8 inches is 11.2 inches longer than that of said S-class, explaining the palatial interior feeling. Besides the pretty comfortable seats for four grownups, sound in the interior is wonderfully muffled by the one-millimeter-thick cork veneer that bathes several surfaces. Director of group research and advanced engineering for vehicle concepts and human factors (and owner of the longest job title in the Daimler group) Gunther Ellenrieder explained, “Cork is lighter than leather, and we wanted a very natural-feeling surface treatment that meshed with the more efficient technologies of the car.”

The DiesOtto 1.8-liter engine with two-stage turbocharging does what gas engines do best: it runs naturally cleaner and quieter than diesel, costs less to build and buy, and provides good horsepower, while also doing what a diesel does best—namely running efficiently and creating a lot of torque. Initially we were skeptical of any four-cylinder engine driving a stretched S-class, thinking that it would be suitable only for freelance chauffeurs. Riding with the DiesOtto in the 3750-pound F700 and then driving it in a roughly 4300-pound S-class revealed to us that this is a downsizing trend that will take hold in this upper segment sooner or later. The current powertrain creates 235 horsepower with the engine and 20 horsepower more from the electric motor (255 horsepower total) with its starter-generator integrated within the housing for the 7G-Tronic automatic transmission. Cumulative torque is rated at 295 pound-feet and is all available from very low in the rev count, which helps explain the respectable acceleration to 62 miles per hour of just 7.5 seconds. This is a package that, in the end, roughly equates to either the Daimler 3.5-liter gas V-6 or 3.0-liter CDI turbo-diesel experience.

Anytime the F700 comes to a halt, the engine stops and the subsequent re-launch happens via the electric motor, so there is also the popular hybrid aspect to all this. At no time while guiding the system around the track did we feel brusque transitions between either the electric and internal combustion modes or between the conventional combustion cycle using spark plugs during heavier throttle input and the “controlled auto-ignition” (i.e. the diesel-style combustion part) phases under light loads and while cruising.

The compression ratio ranges between 7.0:1 and 14.0:1, and the direct injection allows for a much cleaner burn in all conditions. Basically, the DiesOtto attempts to combine all of the strengths of current leading technologies while doing away with the need for the complex and heavy after-treatment systems of Bluetec diesel. Overall operating temperatures are kept low by removing the hot peaks associated with normal spark-plug initiated combustion, and this in turn does away with most all of the nitrogen oxides. Hence a relatively low-tech three-way catalytic converter is all that is needed to clean up the exhaust fumes. Total average CO2 emissions per mile are extremely low at 204 grams, while average mileage of the system hits at least 44.3 miles per gallon.

Underneath us at all four corners, meanwhile, the interesting new Pre-Scan suspension was working overtime, sucking up the bumps ahead. This is a laser-based system (created by a company with the unfortunate acronym S.U.C.K.) with two of the infrared units in each headlight assembly. The beams start reading things in detail at about fifty feet in front of the car, and the bounced-back image grows clearer right up to ten feet in front. Needless to say, these beams work ridiculously fast, and the special dampers do a remarkable job.

Leaving the chassis in default Active Body Control in our other S-class tester, we felt the capabilities of this currently available setup in comfort mode. Right after that, we approached the same bumps with Pre-Scan activated, and the level of the car never changed while we rode over them. Then we did the same on alternating bumps side to side, and the effect was the same. Imagine a bird of prey on the hunt for dinner, sitting on a branch while the wind blows, but the bird’s head stays frozen still. It’s the same deal here, and it feels a bit odd.

There’s no doubt that both DiesOtto and Pre-Scan will work their way into production, most likely on the next-generation S-class to begin with. Think 2011 or 2012.