Ford Mustang Owner's Manual page 205

Maintenance and Specifications
Letter rating
Y
Note: For tires with a maximum speed capability over
240 km/h (149 mph), tire manufacturers sometimes use the
letters ZR. For those with a maximum speed capability over
299 km/h (186 mph), tire manufacturers always use the
letters ZR.
8. U.S. DOT Tire Identification Number (TIN):
This begins with the letters "DOT" and indicates that
the tire meets all federal standards. The next two
numbers or letters are the plant code where it was
manufactured, the next two are the tire size code
and the last four numbers represent the week and
year the tire was built. For example, the numbers
317 mean the 31st week of 1997. After 2000 the
numbers go to four digits. For example, 2501 means
the 25th week of 2001. The numbers in between are
marketing codes used at the manufacturer's
discretion. This information is used to contact
customers if a tire defect requires a recall.
9. M+S or M/S: Mud and Snow. or
AT: All Terrain. or
AS: All Season.
10. Tire Ply Composition and Material Used:
Indicates the number of plies or the number of
layers of rubber-coated fabric in the tire tread and
sidewall. Tire manufacturers also must indicate the
ply materials in the tire and the sidewall, which
include steel, nylon, polyester, and others.
11. Maximum Load: Indicates the maximum load in
kilograms and pounds that can be carried by the
tire. Refer to the tire label or the safety certification
label, located on the B-Pillar or the driver's door, for
the correct tire pressure for your vehicle
12. Treadwear, Traction and Temperature
Grades
• 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
2004 Mustang (mus)
Owners Guide (post-2002-fmt)
USA English (fus)
Speed rating - km/h (mph)
299 km/h (186 mph)
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