COMMERCIAL TIRES

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.

Remember!

Serious injury may result from explosion of the tire/rim assembly due to improper mounting – never exceed 40 psi (275 kpa) to seat beads – mount only on designed diameter rims – only specially trained persons should mount tires.

Tires need to have air pressure checked regularly but it must be done while the tires are COLD!

All tires should have their air pressure checked on a regular basis, preferably weekly for truck tires and at least once a month for passenger car tires.

Truckers and motorists who get in the habit of checking their tires on a regular schedule will experience far fewer tire failures and, as an added benefit, will find that their tires last longer and their fuel costs will decline.

TRIB recommends setting a regular weekly or monthly schedule for checking air pressure. A properly maintained and regularly calibrated tire gauge should be used, and the tires must have their air pressure checked while the tires are cold, preferably having been driven for less than one mile.

A good time to check tires is first thing in the morning after the vehicle has been sitting for several hours or longer. This will insure that the tire inspections and air pressure checks are being made while the tires are cold.

The time it takes to visually inspect and maintain proper air pressure in tires is an investment that fleets and motorists really can’t afford not to make.

Different axle loads, different speed requirements, different service conditions — in determining proper air inflation pressure, all kinds of factors enter into the mix. A semi hauling 50,000 gcw at 65 mph doesn’t need the same tire inflation as a 65-mph vehicle approaching 80,000 lbs.

In general, running trucks at normal speeds for prolonged periods with inflation pressures just 20 percent under what is recommended can reduce tire mileage by 16 percent and fuel mileage by 2.5 percent. If you err in inflation pressures, experts will tell you it’s better to be overinflated than underinflated.

Checking and correcting psi in the middle of a hot day or after driving for several hours is a common way to shortchange your tires. During normal service, inflation pressures can increase 10 to 15 psi due to increased casing heat. If you bleed out this overage, your tires will be 10 to 15 psi under inflated after they cool.

To determine the proper air inflation pressure for your tire loads, refer to load and inflation tables. Determine the maximum load your tire is likely to encounter, then find the correct load in the table that is close but slightly more than the maximum you expect.

• Inflate for maximum load your tire must carry
• Check psi when tire is cold
• Use flow-through metal valve caps
• Use air dryers in your system to avoid introducing moisture

When selecting new tires, compare the total value instead of only the upfront price. A tire that costs more today may provide better performance, longer wear, and better driving satisfaction over thousands of miles.

For example, if you plan to drive another 30,000 miles and are comparing a perfect set of tires at $100 each with another set at $90 each, the cost difference per mile may be very small. Saving a little today may not be worth giving up the better tire you will rely on for the next few years.