The new Mercedes-Benz SLK: Passion meets efficiency - Daimler

accelerator, the transmission is shifted to R, the transmission is shiftedfrom P, the driver releases the brake pedal and Hold is not activated.• With a manual transmission, there is always an automatic restart whenone of the following conditions is met – the driver operates theaccelerator, the driver operates the clutch.Page 31Restarting the engine (auto-start function) takes place almost imperceptibly;and moving off without any noticeable time lag compared to a stationaryvehicle with its engine running. This is because the new start/stop system usesstarter-supported direct-start. This means that when the engine stops, a newcrankshaft sensor identifies the rotational position of the crankshaft andenables the engine control unit to identify the cylinder in which the piston isideally positioned for restarting. The fuel is injected into this cylinder first,thereby speeding up the starting process. The engine is then briefly turnedover by the starter, immediately making reliable injection, ignition andcombustion possible. On restarting, a reduced fuel quantity can be injecteddirectly into the first cylinder to ensure a fast starting procedure, e.g. at trafficlights.An additional electric transmission oil pump supplies the clutches of theautomatic transmission with oil pressure prior to starting, so as to enable aswift resumption of the journey after direct starting of the combustion enginevia the ECO start/stop function. The starter motor (starter) has also undergonethorough modification: it is now designed to cope with eight times as manystarting procedures, ensuring that it will last a car's lifetime in continuousurban driving involving frequent auto-starting. In addition, the on-boardelectrical system is supported by a second battery.Automatic transmission with fuel economy benefitsThe SLK 200 BlueEFFICIENCY is equipped with the familiar 6-speed manualtransmission, which excels with a short, sporty shift travel. The improved7G-TRONIC PLUS seven-speed automatic transmission is available for thismodel as an option, and is standard equipment for the other two enginevariants (a 6-speed manual transmission will be available as an alternative forthe SLK 250 BlueEFFICIENCY at a later date). It has undergone extensivefurther development with the aim of achieving an engine connection withfurther decreased torque converter slip, a significant reduction in internallosses and therefore optimised efficiency. Mercedes-Benz developers subduedeccentricities and vibrations in the transmission by incorporating a newDaimler Communications, 70546 Stuttgart/GermanyMercedes-Benz – A Daimler Brand