INFORMATION ABOUT UNIFORM TIRE QUALITY GRADING
Tire Quality Grades apply to new
pneumatic passenger car tires. The
Quality grades can be found where
applicable on the tire sidewall
between tread shoulder and
maximum section width. For
example:
•Treadwear 200 Traction AA Temperature A
These Tire Quality Grades are determined by standards that the United
States Department of Transportation has set.
Tire Quality Grades apply to new pneumatic passenger car tires. They do
not apply to deep tread, winter-type snow tires, space-saver or
temporary use spare tires, light truck or “LT” type tires, tires with
nominal rim diameters of 10 to 12 inches or limited production tires as
defined in Title 49 Code of Federal Regulations Part 575.104(c)(2).
U.S. Department of Transportation-Tire quality grades:The U.S.
Department of Transportation requires Ford Motor Company to give you
the following information about tire grades exactly as the government
has written it.
Treadwear
The treadwear grade is a comparative rating based on the wear rate of
the tire when tested under controlled conditions on a specified
government test course. For example, a tire graded 150 would wear one
and one-half (1
1 2) times as well on the government course as a tire
graded 100. The relative performance of tires depends upon the actual
conditions of their use, however, and may depart significantly from the
norm due to variations in driving habits, service practices, and
differences in road characteristics and climate.
Traction AA A B C
The traction grades, from highest to lowest are AA, A, B, and C. The
grades represent the tire’s ability to stop on wet pavement as measured
under controlled conditions on specified government test surfaces of
asphalt and concrete. A tire marked C may have poor traction
performance.
2009 Grand Marquis(grn)
Owners Guide(own2002), 2nd Printing
USA(fus)
Tires, Wheels and Loading
138
Use of one of the dissimilar spare tires listed above at any one wheel
location can lead to impairment of the following:
•Handling, stability and braking performance
•Comfort and noise
•Ground clearance and parking at curbs
•Winter weather driving capability
•Wet weather driving capability
3.Full-size dissimilar spare without label on wheel
When driving with the full-size dissimilar spare tire/wheel,do not:
•Exceed 70 mph (113 km/h)
•Use more than one dissimilar spare tire/wheel at a time
•Use commercial car washing equipment
•Use snow chains on the end of the vehicle with the dissimilar spare
tire/wheel
The usage of a full-size dissimilar spare tire/wheel can lead to
impairment of the following:
•Handling, stability and braking performance
•Comfort and noise
•Ground clearance and parking at curbs
•Winter weather driving capability
•Wet weather driving capability
•All-Wheel driving capability (if applicable)
•Load leveling adjustment (if applicable)
When driving with the full-size dissimilar spare tire/wheel additional
caution should be given to:
•Towing a trailer
•Driving vehicles equipped with a camper body
•Driving vehicles with a load on the cargo rack
Drive cautiously when using a full-size dissimilar spare tire/wheel and
seek service as soon as possible.
2009 Grand Marquis(grn)
Owners Guide(own2002), 2nd Printing
USA(fus)
Roadside Emergencies
196
