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. ...

Cleaning the wheels
Do not use acidic wheel cleaning products to remove brake dust. This could damage wheel bolts and brake components. Do not park the vehicle for an extended period straight after clean ...

Making adjustments in 1 mph (Canada:

1 km/h) increments
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. ...