On starting and at full load, the air-fuel mixture is not ignited by a sparkplug as in a conventional gasoline engine. The controlled auto ignition (homogeneous combustion) to which the DIESOTTO automatically reverts within its working cycle occurs under partial load conditions, i.e. at low and medium engine speeds.
As a result of homogeneous combustion at reduced reaction temperatures, very 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. In addition, in order to combine the individual subsystems into one drive concept, a highly efficient engine management and control system has been implemented.
The drive unit of the F 700 is a compact four-cylinder with a displacement of 1.8 liters, and yet it ensures that feeling of effortless, superior power afforded by a luxury sedan: a two-stage turbocharger system ensures good response and torquey pulling power. In addition, when the car moves off the internal combustion engine is assisted by the electric motor of the hybrid module. The maximum output is 175 kW (238 hp), the electric motor pitches in another 15 kW (20 hp), and the system’s maximum torque is about 400 Newton meters. The 0 to 100 km/h (62 mph) sprint time of 7.5 seconds attests to the dynamics of the F 700, whose top speed is limited to 200 km/h. Despite these outstanding performance figures, the consumption of the F 700 in the standard cycle is only about 5.3 liters, equivalent to CO2 emissions of 127 grams per kilometer – extremely low for an automobile of this category.
Anticipatory intelligence packed into the suspension
Similar advances are made by the F 700 in the area of ride comfort. Mercedes-Benz has always been a leader in the area of road roar/tire vibration characteristics and suspension comfort: the Active Body Control suspension system in the CL-Class, S- and SL-Class sets the standard worldwide with its unrivaled combination of comfort, handling safety and dynamics. This system is now surpassed by the new technology of the F 700.
For here, once again, the new research car takes an important step to the future: thanks to its active PRE-SCAN suspension, the vehicle not only responds with great sensitivity to roadway unevenness; more than that, it acts with foresight.
PRE-SCAN uses two laser sensors in the front headlamp units as “eyes”. They deliver a precise image of the condition of the roadway. Based on the image supplied by the laser sensors and the information on the vehicle state, the control unit figures out a specific strategy which the high-pressure hydraulics translate into precisely calculated fluid flows and pressures for each single wheel.
