Mercedes-Benz F 700 Redefines Green Luxury

Visionaries and dreamers make the automobile industry exciting and move car design and technology forward. A prime example of such effort is the Mercedes-Benz F 700 research car, a luxury dream car inspired by long-term vision. An evolution in the series of more than 20 vehicle explorations Mercedes has created since its Auto 2000 research car in 1981, F 700 is a revolutionary step on many fronts.

Mercedes describes the F 700 concept as a "forward looking combination of refinement and environmental friendliness." With the F700, Mercedes-Benz has introduced its new DIESOTTO powertrain technology. The company is convinced that internal combustion engines can power personal transportation for many years to come given improvements in all dimensions. DIESOTTO combines diesel economy with the convenience and low emission of gasoline powered cars.

According to Dr. Thomas Weber, a Board member of Daimler AG responsible for Group Research & Mercedes Car Group Development, "Our strategic objective is to make the gasoline-powered car as economical as the diesel and the diesel as clean as the gasoline." BLUETEC technology introduced to the U.S. market in the Mercedes-Benz E320 sedan has implemented the clean diesel program. The next step is raising the fuel economy of gasoline internal combustion powertrains.

DIESOTTO employs downsized engine displacement along with many advanced technologies including direct injection, turbocharging, controlled auto ignition, and variable valve control. A hybrid electric module with an internal starter-generator is also used to achieve peak efficiency with impressive power. The F 700's DIESOTTO powertrain takes the small displacement theme to the extreme for this size car with a mere 1.8-liter four-cylinder gasoline engine housed under the sculptured hood. Combining DIESOTTO technology with twin two-stage turbochargers — one small for low rpm and a larger one for high rpm — the four-cylinder produces 238 horsepower, on par with a 3.5-liter V-6 gas engine or a Mercedes 3.0-liter diesel.

The DIESOTTO powertrain is unique in that it combines the spark ignition of a gasoline engine with the compression ignition of a diesel. Fuel and air are injected into the cylinders and fired by a spark plug from start and under most operating conditions. When the cylinders reach the appropriate temperature, the DIESOTTO seamlessly transitions to diesel mode and fires on compression. Once the engine's spark plugs are deactivated, the high-tech variable crankshaft mechanism changes profile to raise cylinder compression and ignite the mixture like a diesel.

The F 700's hybrid side offers a 20 hp (15 kW) electric motor to supplement the DIESOTTO internal combustion engine for a total power output of 258 horsepower and 295 lbs-ft of torque. Acceleration from 0 to 62 mph is said to be in the mid-seven second range, quite good for this size luxury car, all the while providing quite extraordinary fuel efficiency.

By extraordinary, we mean a claimed fuel economy of just over 44 mpg on the European test cycle, considerably better than the current S350 sedan. Emissions are on par or better than most small cars, emitting just 204.4 g/mile of CO2.

Economy and emissions are just part of the story. The F 700 just bristles with advanced technology as this "forward-looking concept" does indeed look forward. Two laser sensors housed in its futuristic headlight units scan the road ahead to read driving conditions, and then adjust the suspension accordingly through a high-pressure hydraulic system. The headlights offer two rows of linear LED arrays with superimposed lenses for sure illumination under challenging lighting conditions.

The F 700 is said to provide design cues for the 2012 Mercedes-Benz sedans. In a word, the form is "stunning." Mercedes aptly portrays the F 700 design as one in which "tense lines create stretched elegance." It's aggressive and pushes the limits of accepted luxury sedan design with a decided performance theme. The form is solid as though milled from a single billet, providing a very reassuring overall feel.

Though it has a decidedly German look, the F 700 is a product of the Mercedes-Benz advanced styling studio in Irvine, California. The studio coined this new look as "Aqua Dynamic," which describes the flowing yet strong lines quite well.

Inside, the F 700 owes its interior design to the Mercedes-Benz advanced interior studio in Lake Como, Italy. Warm and inviting, the cabin is a pleasant contrast to the vast amount of technology in this car. The interior features natural materials including rich leather upholstery and cork trim in an earthy brown and beige color scheme. One of the most unique features is an adaptable seating configuration that can change depending on the mission. With the push of a button, the right rear seat slips into a "relax" mode in a rear-facing reverse position, allowing the occupant to recline and enjoy a large video display that opens out of the rear package shelf area. Surround sound augments the futuristic 3D technology built into the display.

There's a lot more advanced wizardry housed in the F 700, like human-machine interface technology to reduce driver fatigue and voice recognition with a virtual operating assistant to facilitate control of the complex systems. If this is the future of the luxury touring sedan ... then sign us up. Who says environmentally friendly requires sacrifice?