March 17, 2015 by Minuteman Trucks
Ford research has determined tires degrade over a period of time due to such factors as weather, storage conditions, and type of use including load, speed and inflation pressure.
Heat or frequent high load conditions can accelerate a tire’s aging process. Signs of aging include cracking of the tread and sidewall rubber. As not all signs of tire aging are visible, Ford recommends all tires, including an unused spare, be replaced after six years regardless of wear due to the possible effects of aging.
Ford recommends vehicle owners also inspect the tread of their tires for uneven or excessive wear at least once a month. Built-in tread wear indicators, also known as wear bars, appear on the tire when the tread reaches one-sixteenth of an inch, or 2 millimeters. Wear bars look like narrow strips of smooth rubber across the tread grooves. A tire should be replaced if its tread is worn down to one-sixteenth of an inch.
When inspecting their vehicle tires, motorists are reminded to:
- Check the last four digits of the U.S. Department of Transportation (DOT) Tire Identification Number, located on the tire sidewall, to determine the week and year it was manufactured. The last two digits show the year the tire was made
- Watch for DOT Tire Identification Numbers that end in three digits. Those tires were manufactured prior to 2000 and need to be replaced
- Check for signs of aging, such as cracks on the tread and sidewall, as well as any deformation to a tire’s exterior
- Remove objects – such as stones, nails or glass – that can become wedged in the tread grooves
- Check valve stems for holes, cracks or cuts that can cause air leakage
- Check sidewalls for cracks, cuts, bruises, bulges or excessive wear; if internal damage to a tire is suspected, the tire should be removed and inspected for potential replacement
How driving behavior impacts tire wear:
A motorist’s driving can have an impact on tire wear and safety. Hitting potholes and curbs can result in tire damage and changes in a vehicle’s alignment. If a vehicle seems to pull to one side while driving, this could indicate the wheels are out of alignment – resulting in uneven and rapid tire tread wear.
Follow these tips to avoid damaging your tires:
- Observe posted speed limits, avoid potholes and objects in the road, and take care when parking not to run over curbs or allow tires to come in contact with a curb
- Periodically have tires balanced to avoid uneven wear, and seek assistance from an authorized dealer to check for and correct any wheel misalignment or other mechanical problem if tires do show uneven wear
- Rotate tires at the recommended intervals indicated in the scheduled maintenance section of the owner’s manual. This helps tires wear more evenly and will lead to better performance. After rotating, tire inflation pressures must be checked, and adjusted if needed, to the level indicated on the safety compliance certification label, which can be found on either the driver’s-side door hinge pillar, the door latch post, or where the door edge meets the door latch post
Tire risks in the winter months
Changes in temperature can have an effect on tire inflation, with a 10-degree drop in temperature causing a corresponding drop of 1 psi in tire pressure.
It is particularly important during the winter that vehicle owners check their tires at least once a month, and – when necessary – adjust tire pressure to the proper level of inflation indicated on the safety compliance certification label.
This reminder follows the recent TireWise campaign initiated by the National Highway Traffic Safety Administration. For more information, visit the TireWise website, www.safercar.gov/tires.