|Mercedes’s concept “Direct Hybrid”: an S-Class gasoline-electric mild hybrid, shown in 2005|
Handelsblatt. DaimlerChrysler will bring a Mercedes gasoline-electric hybrid to the market by the beginning of 2008, according to DaimlerChrysler Board Member Dr. Thomas Weber.
In an interview with the magazine WirtschaftsWoche, Weber said that the company will commercialize an S-class mild hybrid, and that further mild-hybrid models are in development for subsequent years.
At last year’s Frankfurt auto show, DaimlerChrysler introduced both gasoline and diesel Mercedes mild-hybrid concept cars based on the S-Class. (Earlier post).
|The S350 Direct Hybrid is based on a new V6.|
The S350 “Direct Hybrid” prototype is a V6 gasoline hybrid that uses DaimlerChrysler’s second-generation spray-guided gasoline direct injection in a 3.5-liter, 4-valve V6 with fully variable valve timing.
With the spray-guided direct injection process, the Direct Hybrid 3.5-liter V6 generates an output of 215 kW (292 hp) at 6,000 rpm. Its maximum torque of 365 Nm is already accessible at 2,400 rpm and remains available over a broad range of engine speeds up to 5,000 rpm.
The exhaust treatment for this layered direct injection process takes place in the double-stream exhaust system. A NOx trap system for reducing the nitrogen oxides is also used, in addition to the two bulkhead catalytic converters and controlled recirculation of exhaust gas in each branch. The results meet both current Euro-4 exhaust emissions standards and the forthcoming Euro-5 limits.
A 6kW electric motor is installed between the concept’s engine and the 7G-TRONIC automatic transmission’s converter. Depending on the driving situation, it functions as a starter or a generator, and provides a tractive boost on startup—up to 250 Nm upon ignition, with 50 Nm of torque at 1,000 rpm—and at other points during operation.
The S350 concept uses a lithium-ion battery pack for energy storage.
The combination of motor and engine boosts the maximum available torque to 395 Nm and makes the vehicle’s starting characteristics powerful.
The concept mild Direct Hybrid consumes 8.3 liters of gasoline per 100 km (34 mpg US). Compared with its predecessor model, the S 350 V6, the power has been increased by 19% and the consumption cut by 25%.