See also:

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. ...

Uniform Tire Quality Grading Standards
A uniform standard to grade the quality of tires with regards to tread quality, tire traction and temperature characteristics. Ratings are determined by tire manufacturers using U.S. government ...

Making adjustments in 5 mph (Canada:

10 km/h) increments
Briefly press the cruise control lever beyond the pressure point, up 1 for a higher speed or down 2 for a lower speed. The last speed stored is increased or reduced. ...