For many decades now, our research vehicles have been turning pioneering concepts into reality and thereby setting future trends. We set a course on the large touring sedan segment in 2007, when we presented the F 700. [Earlier post.] Characteristic features of the F 800 Style are its innovations, whose development is already close to the series production stage. This is true not only of the electric drive with fuel cells but also of the Plug-in Hybrid, whose components were taken from our modular system for electric and hybrid vehicles.

—Prof. Herbert Kohler, Head of E-Drive & Future Mobility and Chief Environmental Officer at Daimler

(At the recent SAE 2010 Hybrid Vehicle Technology Symposium, Dr. Neil Armstrong, Chief Engineer/Director, Hybrid Systems and Components for Daimler, noted the importance for Daimler of the ability for leveraging system components across drive types as embodied in the BlueZero modular electric drive platform (earlier post.)

F 800 Style Plug-in Hybrid. The drive unit of the F800 Plug-in Hybrid consists of a V6 gasoline engine with an output of approximately 220 kW (300 hp) with next-generation direct injection and a hybrid module with an output of about 80 kW (109 hp), combined for total power of around 300 kW (409 hp). The lithium-ion battery with a storage capacity of >10 kWh can be recharged either at a charging station or a household power socket.

F800 Plug-in Hybrid, Gasoline
Specs
Engine output (kW/hp)	Approx. 220/300
Electric motor output (kW/hp)	Approx. 80/109
Total output (kW/hp)	Approx. 300/409
Li-ion pack capacity (kWh)	>10
Total range (km/miles)	Approx. 700/435
CO2 (g/km)	68
Emissions rating	EU6	Click image to enlarge.

The F 800 Style with the Plug-in Hybrid can run purely on electricity for up to 30 kilometers (19 miles). The F 800 Style research vehicle marks a further step in the development of a market-ready plug-in hybrid from Mercedes; Mercedes-Benz has said it plans to begin series production of the S 500 Plug-in Hybrid with the introduction of the next-generation S-Class. (Earlier post.)

From a design standpoint, the hybrid module with around 80 kW output in the F 800 Style differs only slightly from the 44 kW variant used in the Vision S 500 Plug-in Hybrid. Whereas the lithium-ion battery in the Vision S 500 Plug-in Hybrid was placed behind the rear seats, the electric storage unit is now located under the rear seat in the F 800 Style. This installation location ensures the greatest possible crash safety, good driving dynamics thanks to the vehicle's low center of gravity, and unrestricted space in the interior of the vehicle. The 45-liter gasoline tank is mounted behind the rear seat backrests, again in the interest of crash safety and to save space. The result is a 440 liters of trunk space.

In designing the F 800 Style with Plug-in Hybrid, the Mercedes engineers particularly focused on improving the possibilities of driving exclusively with electricity in urban traffic.

One system-specific attribute of the familiar hybrid concept from the S 500 Plug-in Hybrid is the clutch integrated between the combustion engine and the electric motor. This device decouples the two components in the pure electric drive mode, thereby ensuring the highest level of efficiency without engine drag losses. Moreover, because it is fully integrated into the converter housing of the seven-speed 7G-TRONIC automatic transmission—as is the case with the Mercedes-Benz S 400 HYBRID introduced in the summer of 2009 and the Vision S 500 Plug-in Hybrid—this clutch does not take up any additional space.

The Li-ion traction battery is cooled via a separate cooling water loop connected to the research vehicle’s climate control system to ensure that the battery is cooled within an optimal temperature window. The plug-in battery of the F 800 Style can be charged both at charging stations and via a conventional household outlet.

The vehicle has a certified fuel consumption of 2.9 liters of gasoline per 100 kilometers (81 mpg US), with corresponding CO₂ emissions of 68 grams per kilometer. Acceleration from 0-100 km/h takes 4.8 s, and the vehicle has a top speed of 250 km/h (155 mph). When in electric mode, the F 800 Style has a top speed of 120 km/h (75 mph).

The F 800 Style with electric drive and fuel cell technology. In the fuel cell variant, the F 800 Style’s electric motor develops around 100 kW (136 hp) as well as torque of approximately 290 N·m (214 lb-ft). The components of the fuel cell drive are taken from the range of e-drive modules which Mercedes-Benz developed for a variety of different electric vehicles.

F800 with F-CELL
Specs
Rated output (kW/hp)	Approx. 100/136
Rated torque (N·m)	Approx. 290
Li-ion capacity (kWh)	1.4
Max speed (km/h)	180
H2 consumption (kg/100km)	0.9
CO2 (g/km)	0
Range NEDC (km/miles)	Approx. 600/373	Click image to enlarge.

These components, which are already being installed in the limited edition B-Class F-CELL, can be flexibly used and are suited for a variety of different drive configurations. The F 800 Style is an example of this, as it uses rear-wheel drive, in contrast to the B-Class F-CELL. The same components are also installed in commercial vehicles, with developments here being spearheaded by the new Citaro fuel cell bus, which is equipped with two of the F-CELL systems used in passenger cars.

The new Mercedes-Benz research vehicle has the fuel cell located in the front, while the compact electric motor is installed near the rear axle. The lithium-ion battery is located behind the rear seats and is protected as well as possible against the effects of accidents, as are the four 700-bar hydrogen tanks. Two of the tanks are located in the transmission tunnel between the passengers, while the other two are underneath the rear seat. The tanks can store up to 5.2 kilograms of the gaseous fuel, which is enough for a range of almost 600 kilometers (373 miles).

Range on Map. Mercedes engineers also developed a the Range on Map function, which shows the remaining possible travel radius during electric vehicle operation as a 360° depiction on a map. Should municipalities only permit purely electric automobile traffic in the future, the driver can determine whether the electric range of his or her vehicle is sufficient for the journey into and out of the urban area by means of the Range on Map function. The system provides this function by combining information on the current battery charge level with data from the navigation system.