Today's vehicles are more complex that ever before. We're happy to provide the following Helpful Tips to help you navigate your vehicle maintenance questions.
- Air Pressure Tips
- Understanding Uniform Tire Quality Grade (UTQG) Ratings
- Plus Fitments – Custom Wheels
- Sidewall Information
Air Pressure Tips
Tires don't really carry the weight of your vehicle ... the air pressure inside them does. And the correct air pressure is also required for good handling, traction and durability.
Check inflation pressure
You can't set it and just forget it! In most parts of North America, fall and early winter months are the most critical times to check inflation pressures because the days are getting shorter and temperatures are getting colder. And since air is a gas, it contracts when cooled.
For every 10 degree fahrenheit change in ambient temperature, your tire's inflation pressure will change by about 1 psi (up with higher temperatures and down with lower.)
The typical difference between summer and winter temperatures is about -50 degrees Fahrenheit - which results in a loss of about 5 psi and will sacrifice handling, traction, durability ... and fun!
Check your owner's manual
The tire pressure recommended in your vehicle's owner's manual or tire information sticker is a "cold" pressure, so it should be checked in the morning before you drive more than a few miles.
And by the way, if you park in an attached or heated garage you will "lose" pressure when you leave its warmth and venture into the real world outside.
What is TPMS?
The TPMS constantly monitors your car's tire pressure and alerts you if it falls below a preset limit.
Understanding Uniform Tire Quality Grade (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 treadwear, traction and temperature resistance. These tests are conducted independently by each manufacturer following government values 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 treadwear ratings are assigned by the manufacturers following field testing and are most accurate when comparing tires of the same brand.
Treadwear receives a comparative rating based on wear rate of 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 a tire can vary significantly depending on conditions, driving habits, care, road characteristics and climate.
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" was 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 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.
Plus Fitments – Custom Wheels
When "low profile" looks and performance are desired, install Plus One, Plus Two or Plus Three tire and wheel packages.
Here's How We Do It
We select O.E. equivalent tire diameters and load capacities by matching wider, lower profile tires with wider, larger diameter wheels. This maintains the accuracy of the vehicle's speed dependent systems while helping reduce braking distances, improve responsiveness and increase stability.
You will often find inly +/- two tenths of an inch difference in the overall diameter of the tires. This results in a negligible +/- four tenths of a mph speedometer variance.
Offset is the distance (in mm) between the centerline and the mounting surface of the wheel.
Wheel offset is very important in maintaining the handling characteristics of your vehicle. Improper offset can wear tires faster and lead to unpredictable, unsafe performance.
Maintaining Proper Offset
As you change your vehicle's wheel width you may need to vary the offset from the O.E. specifications to maintain proper suspension geometry. Call us. We know the proper combinations for your vehicle.
Used with permission by: Tire Guides, Inc., Boca Raton, FL