A dramatically styled Mercedes-Benz research vehicle unveiled at Frankfurt showcases a series of high-end features the company plans to incorporate into future production models.

Dubbed the F700, the large luxury sedan plots a direct path to the next-generation S-Class due in 2012, with state-of-the-art engine and suspension technology, as well as an advanced avatar-based controller system and radical new styling developed by the German automaker's U.S.-based design studio in California.

Mercedes describes the F700 as a "futuristic interpretation of the classic sedan" and predicts much of the technology it previews will begin appearing on production models within the next decade as emissions regulations become more stringent and buyer expectations grow with advances in fields such as consumer electronics.

While officials are quick to downplay the relevance of the new four-door's styling, Mercedes sources suggest that various themes explored within its body are likely to be developed further before being committed to production, including a bold front-end treatment said to preface the look of its future lineup, as well as individual elements such as prominent wheel arches and flowing C-pillars.

In a novel approach, Mercedes has provided the F700 with three conventionally hinged doors and a fourth rear-hinged door at the rear on the right, designed to facilitate entry and exit for those seated in the right rear, which can be either set in the direction of travel or turned 180 degrees.

More than its radically styled exterior, however, it is the one-off sedan's compact variable-compression, twin-turbocharged, 1.8-liter four-cylinder DiesOtto gasoline engine that Mercedes promises will have the biggest bearing on its future model range. Claimed to offer the power, smoothness and low emissions of a gasoline engine in combination with the torque, flexibility and frugal properties of a diesel, the new unit is capable of switching between spark and compression ignition, depending on the driving conditions.

Despite its relatively meager capacity by luxury-car standards, the F700's advanced engine punches well above its weight, with a 238-hp output that compares favorably with Mercedes' existing four-valve-per-cylinder 3.5-liter V6 gasoline and 3.0-liter V6 common-rail diesel units. With an electric motor designed to provide an additional burst of output under acceleration, the F700's peak power tops out at a competitive 258 hp in hybrid mode. Torque is rated at 295 lb-ft. Mercedes says it's enough to propel the F700 from 0 to 62 mph in 7.5 seconds. It's estimated to get more than 50 mpg with an extremely low carbon-dioxide output.

Another feature Mercedes is touting for possible inclusion on future production models with the F700 is a highly sophisticated Pre-Scan suspension system. The system reads the road via two headlamp-mounted sensors, which constantly send out infrared beams to detect unevenness in the roadway and driving conditions. Information is then relayed to the suspension and associated driving aids so they can react before you've even hit an imperfection or wet section of blacktop.

You may e-mail Greg Kable at autonews@crain.com