By Jeff Dusing
Tyres are parts of your car that wear out as a result of normal use. Fortunately, tyres rarely fail without warning, and this warning often comes in the form of abnormal wear. In fact, tyres are excellent at telling you whether or not they are wearing normally and, if not, what is to blame. We’ll give you some key symptoms to look for and suggest some easy corrections.
Upon examining your tyres, you’ll find the two primary parts are the tread and the sidewall. The tread is reinforced by multiple steel belts that provide additional protection against puncture. The sidewall is not.
Because of this difference, you will want to begin any tyre inspection with a careful examination of the tyre sidewall. Look for any cuts, bubbling or cracking. If you find any of these, take your tyres to a local tyre retailer immediately for a professional inspection. Because of the delicate nature of the tyre sidewall, it is advisable to install your spare tyre before driving.
In addition to the tyre sidewall, you’ll want to give the tread a thorough inspection. Start your review by checking the depth of the tyre tread. This will give you an idea of how many pleasant drving kilometres you’ve got left before some new rubber is required.
Every tyre is equipped with several tyre wear indicators that run across the tread in the grooves between the tread ribs. Once these tyre wear indicators are flush with the ribs, it is time to replace the tyre.
During your examination, you will also want to check for any abnormal wear. If the tyre tread depth is uneven, be sure to find out where the wear is occurring. You should be able to determine its source and, if it’s not too late, correct it before you reduce the rest of your tyre’s useful life. There are four common causes of premature tyre wear: improper inflation, misalignment, lack of rotation and front-end wear.
Proper inflation is essential for normal wear on your tyres. If your tyres are underinflated, the sidewall will sag, causing excessive wear on the outside areas of the tread. Under-inflation also results in excessive heat, which accelerates wear and may cause a blowout.
Tyres that are overinflated will show wear down the middle, with the outside edges remaining in relatively good condition. This, too, is a bad thing, causing accelerated wear that will decrease your tyre’s life. Try dropping the pressure down a few pounds to even out the wear on the tyres.
The key here is checking your tyre pressure at least twice a month. Manufacturer-recommended tyre pressures are usually printed on a label that is placed in the driver’s-side doorjamb. When filling your tyres, note the average outside temperature. Hotter temperatures will expand the air in your tyres, raising the pressure by a few pounds, and cooler temperatures will cause a reduction in pressure. This is another good reason to check your tyre pressure regularly.
When the wheels of a vehicle are out of alignment, this may also cause unusual and excessive tyre wear. Tyres that are heavily worn on one side or the other are riding at an angle and not flat on the ground. A side effect of this condition is decreased traction due to reduced contact with the road. See your local tyre retailer to determine if a wheel alignment will resolve the condition.
A third aspect of any good tyre inspection should include a comparison between the tread depths on the front and the rear tyres. The rubber on the front of your car will diminish much faster than that on the rear due to increased friction when turning. The difference in wear between front and rear is amplified on front-wheel-drive cars. The simple solution for this occurrence is regular tyre rotation. Front tyres will always wear faster, but by swapping the front and rear tread every 10,000 to 15,000 kilometres, all tyres will wear evenly in the end.
Remember, some vehicle types and tyre combinations require particular rotation patterns. Refer to your car owner’s manual for the recommended tyre rotation pattern, observing the proper wheel lug tightening sequence and specified torque values.
The final step before you pass your tyre inspection test is to make sure the tread is wearing evenly around the circumference of the tyre. Poorly balanced wheels or worn front-end components may cause the tyre to bounce on the road, causing a condition known as cupping. This condition, also known as scalloping, dipping and feathering, causes areas of the tread to wear more rapidly, which makes the tyre out of round. As a result, the normally smooth tread suddenly has peaks and tips every few inches all the way around. And unless you have very expensive and highly specialized equipment, the only way to correct this condition is to consult a professional repair facility for a thorough diagnosis.
Now that you know the basics of tyre inspection, get out there and check your tyres. By keeping abnormal wear to a minimum, you’ll be safer on the road and save some money by replacing your tyres less often.