DSR (Downhill Speed Regulation)

See also:

Treadwear indicators
Narrow bars (tread wear bars) that are distributed over the tire tread. If the tire tread is level with the bars, the wear limit of 1/16 in (1.6 mm) has been reached. ...

Tire size designation, load-bearing capacity and speed rating
1 Tire width 2 Nominal aspect ratio in % 3 Tire code 4 Rim diameter 5 Load bearing index 6 Speed rating Tire data is vehicle-specific and may deviate from the data in the example. ...

Important safety notes
DSR is an aid to assist you when driving downhill. It keeps the speed of travel at the speed selected on the on-board computer. The steeper the downhill gradient, the greater the DSR braking eff ...