Specifications

What do the Tire Wear Ratings mean?
Uniform Tire Quality Grading - UTQG Ratings
The Department of Transportation requires each manufacturer to grade its tires under the Uniform Tire
Quality Grade (UTQG) labeling system and establish ratings for tread wear, traction, and temperature
resistance. These tests are conducted independently by each manufacturer following government guidelines
to assign values that represent a comparison between the tested tire and a control tire. While traction and
temperature resistance ratings are specific performance levels, the tread wear ratings are assigned by the
manufacturers following field testing and are most accurate when comparing tires of the same brand.
Treadwear:
Treadwear receives a comparative rating based on wear rate of the the tire in field testing following a
government specified course. For example, a tire grade of 150 wears 1.5 times longer than a tire graded
100. Actual performance of the tire can vary significantly depending on conditions, driving habits, care,
road characteristics, and climate.
Traction:
Straight-a-head wet braking traction has been represented by a grade of A, B, or C with A being the
highest. In 1997 a new top rating of "AA" has been introduced to indicate even greater wet braking traction.
However, due to its newness, this grade will probably be applied initially to new tire lines as they are
introduced and later to existing lines which excel in wet braking, but had been limited to the previous top
grade of "A". Traction grades do not indicate wet cornering ability.
Temperature:
Temperature resistance is graded A, B or C. It represents the tire's resistance to the heat generated by
running at high speed. Grade C is the minimum level of performance for all passenger car tires as set under
Federal Motor Vehicle Safety Standards. This grade is established for a tire that is properly inflated and not
overloaded.
Note: UTQG ratings are not required on winter and light truck sized tires.
Engine Cooling Fan Noise
MODELS:
1998 - 1999 (AB) Ram Van/Wagon
1997 - 2001 (AN) Dakota
1998 - 2001 (DN) Durango
DISCUSSION:
Some vehicles may exhibit an engine cooling fan "roar" noise. This noise is created by a large cooling fan
that is required to provide optimum cooling for low vehicle speed operation in hot weather conditions and
for heavy trailer towing. Since the large cooling fan is unnecessary in most operating conditions, these
vehicles are also equipped with viscous fan drives that allow the fan to operate at variable speeds based
upon temperature loads. The viscous fan drive will engage the fan for maximum cooling when
temperatures are high and allow the fan to operate at slower speeds when temperatures are low. In addition,
at engine start-up, the viscous fan drive engages the fan for maximum cooling until the fluid in the viscous
clutch can dissipate out of the clutch drive grooves allowing the fan to operate at a slower speed.
Because of the viscous fan drive, the nois e may occur during high temperature conditions and for the first
1-2 minutes of operation. Due to the roar of the fan, customers may also complain of a perceived loss of
power, automatic transmission slippage, or that the transmission is staying in a low gear too long (delayed