The creators of the Mercedes-Benz F700 research car want to show how outstanding riding quality can be combined with environmental friendliness, and demonstrates that decent performance and exceptionally low fuel consumption are no longer mutually exclusive.
The 5.17m-long F700 is the world's first car that can anticipate and recognise the condition of the road and level out the uneven spots with an active Pre-Scan suspension.
Pre-Scan uses two laser sensors in the front headlamp units as "eyes". They deliver a precise image of the condition of the road. Based on the image supplied by the sensors and the information on the vehicle state, the control unit works out a strategy which the high-pressure hydraulics translate into precise fluid flows and pressures for each single wheel.
The F700 also has a DiesOtto drive system that takes the form of a four- cylinder engine with a displacement of only 1.8 litres, which combines the strong points of a low-emission petrol engine with the consumption of a diesel. Its CO2 emissions of 127g/km and fuel consumption of 5L/100km are extremely low for a vehicle of this class.
DiesOtto technology is an advancement of the internal- combustion engine, says Mercedes, with a controlled auto ignition (CAI), direct fuel injection and turbocharging, which combines the high power of the spark-ignition engine with the torque and economy of a diesel. The drive system in the F700 is a four-cylinder with two-stage charging that achieves the performance of an S-Class model with a 3.5-litre naturally aspirated V6 petrol engine or 3.0-litre V6 turbodiesel.
On starting and at full load, the air-fuel mixture is ignited by a sparkplug as in a conventional petrol engine. The controlled auto ignition (homogeneous combustion) to which the DiesOtto automatically reverts occurs under partial-load conditions, ie, at low and medium-engine speeds.
As a result of homogeneous combustion at reduced reaction temperatures, low emissions of nitrogen oxides are produced. The rest of the emission-control work in the DiesOtto drive is handled by a standard three-way catalytic converter.
Despite a four-cylinder unit of 1.8 litres, the F700 retains its Benz feeling of effortless, superior power. A two- stage turbocharger system ensures good response and pulling power. In addition, when the car moves off the internal combustion engine, it is assisted by an electric hybrid motor. The maximum output is 178kW, the electric motor pitches in with another 15kW, while the system's maximum torque is about 400Nm. A zero to 100km/h time of 7.5 seconds attests to the dynamics of the F700, whose top speed is limited to 210km/h. Despite these figures and the size of the car, its consumption in the standard cycle is only about 53.3mpg (5L/100km) and its emissions just 127g CO2/km.
The F700 also sets standards in regard to road roar, tyre vibration and suspension comfort. With two laser scanners its active Pre-Scan suspension scans the roadway in front of the car. The suspension proactively compensates for detected hindrances, enabling entirely new comfort characteristics _ a "flying carpet" feeling, says Benz.
The information and operating display called Servo-HMI uses an electronic avatar, a virtual assistant, to help with computer and general operating functions.
The avatar in the F700 concept model takes the shape of a young woman, but depending on country and culture, other assistants also can be realised. In the menu item navigation, for example, the avatar asks for a destination. The driver states the address, or a name from the system address book. The avatar confirms it and the route is decided.
Combining the voice-recognition, dialogue systems and individual menu items has advantages: since the virtual assistant polls the required information, the driver does not need to remember specific commands. Conversely, voice recognition works more reliably since the system knows the context of the words spoken.
The exterior design of the F700 looks a little snub-nosed at first, but a large amount of space has been created for the passengers. The car's silhouette, characterised by a huge wheelbase, is clear evidence of such interior volume.
The interior concept interprets comfortable travel and well-being by borrowing from some airlines' business-class innovations and using a reverse seat set-up for the F700. It offers individual seating positions facing, or with ones back to, the direction of travel, as well as spaciousness and comfort.
Overall, the F700 is designed to meet the demand for luxury-class automobiles. But the focus for the car, whose shape and technology is likely to surface in a new S-class sedan before the decade is out, is on conserving resources and the environment.
Hence its low consumption, CO2 emissions, and pollution levels and Benz predicts that in future there will be demand such benefits in large luxury sedans.
