Making adjustments in 1 mph (Canada: 1 km/h) increments

lever to the Briefly press the cruise control lever to the pressure point, up 1 for a higher speed or down 2 for a lower speed.
The last speed stored is increased or reduced.

    See also:

    Vehicle data, GL 550
    The data stated here refers specifically to a vehicle with standard equipment. Consult an authorized Mercedes-Benz Center for the data for all vehicle variants and trim levels. ...

    Adjusting the exterior mirrors
    WARNING   Exercise care when using the passenger-side exterior rear view mirror. The mirror surface is convex (outwardly curved surface for a wider field of view). Objects in mirror are ...

    Coolant temperature display
    WARNING Driving when your engine is overheated can cause some fluids which may have leaked into the engine compartment to catch fire. You could be seriously burned. Steam from an overheate ...