2008 Mercedes R-Class Owner's Manual - Page 260

Controls in detail Driving systems Setting current speed Accelerate or decelerate to the desired speed. Briefly lift the cruise control lever in direction of arrow 1 or depress in direction of arrow 2 ( page 258). The current speed is set. Remove your foot from the accelerator pedal. The cruise control is activated. The currently set speed appears in the status indicator of the multifunction display: USA only: Cruise XXX Miles i On uphill grades, the cruise control may not be able to maintain the set speed. Once the grade eases, the set speed will be resumed. On downhill grades, the cruise control maintains the set speed by braking with the vehicle's braking system. In addition, on longer downhill grades the automatic transmission will downshift automatically. i The cruise control switches off automatically when you step on the brake pedal you depress the parking brake pedal The cruise control switches off automatically and an acoustic warning will sound when the vehicle speed is below 20 mph (30 km/h) the ESP® is in operation the ESP® is switched off with the ESP® switch ( page 104) the ESP® has switched off due to a malfunction ( page 435) you set the automatic transmission to N while driving Observe additional messages in the multifunction display that may appear. Canceling cruise control There are several ways to cancel the cruise control: Step on the brake pedal. The cruise control is canceled. The last set speed is stored for later use. or Briefly push the cruise control lever in direction of arrow 3 ( page 258). The cruise control is canceled. The last set speed is stored for later use. Canada only: Ñ XXX Km/h i The last stored speed is canceled when you turn off the engine. 259