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 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
WARNING:The traction grade assigned to this tire is based on
straight-ahead braking traction tests, and does not include
acceleration, cornering, hydroplaning or peak traction characteristics.
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.
Temperature A B C
WARNING:The temperature grade for this tire is established for
a tire that is properly inflated and not overloaded. Excessive
speed, underinflation, or excessive loading, either separately or in
combination, can cause heat buildup and possible tire failure.
The temperature grades are A (the highest), B and C, representing the
tire’s resistance to the generation of heat and its ability to dissipate heat
when tested under controlled conditions on a specified indoor laboratory
test wheel. Sustained high temperature can cause the material of the tire
Wheels and Tires289
2014 MKX(mkx)
Owners Guide gf, 2nd Printing, March 2014
USA(fus)
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
•All-wheel driving capability
3.Full-size dissimilar spare without label on wheel
When driving with the full-size dissimilar spare tire and wheel assembly,
do not:
•exceed 70 mph (113 km/h).
•use more than one dissimilar spare tire and wheel at a time.
•use commercial car washing equipment.
•use snow chains on the end of the vehicle with the dissimilar spare
tire and wheel.
The usage of a full-size dissimilar spare tire and wheel assembly 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 and wheel assembly,
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 and wheel,
and seek service as soon as possible.
310Wheels and Tires
2014 MKX(mkx)
Owners Guide gf, 2nd Printing, March 2014
USA(fus)
