2005 Mercedes CL-Class Owner's Manual - Page 425

Technical terms Power train Collective term designating all components used to generate and transmit motive power to the drive axles, including: Engine Clutch/torque converter Transmission Transfer case Drive shaft Differential Axle shafts/axles Program mode selector switch Used to switch the automatic transmission between standard operation S and comfort operation C. CL 55 AMG and CL 65 AMG with steering wheel gearshift control and manual shift program: in addition to S and C (see above), you can use M for manual operation REST (Residual engine heat utilization) Feature that uses the engine heat stored in the coolant to heat the vehicle interior for a short time after the engine has been turned off. Restraint systems Seat belts, belt tensioners, air bags and child restraint systems. As independent systems, their protective functions complement one another. RON (Research Octane Number) The Research Octane Number for gasoline as determined by a standardized method. It is an indication of a gasoline's ability to resist undesired detonation (knocking). The average of both the ->MON (Motor Octane Number) and RON (Research Octane Number) is posted at the pump, also known as ANTI-KNOCK INDEX. Shift lock When the vehicle is parked, this lock prevents the transmission selector lever from being inadvertently moved out of position P without the SmartKey turned and the brake pedal depressed. SRS (Supplemental Restraint System) Seat belts, emergency tensioning device and air bags. Though independent systems, they are closely interfaced to provide effective occupant protection. 423