The wheel: arguably, the most influential invention since the dawn of mankind, with the possible exception of homemade fudge, of course.  Without it, we would probably still be hauling things on the tops of our heads and would still consider 40 miles just within walking distance. A long road the wheel has traveled– pun intended– to realize its current design, namely the adoption of the rubber protective cushion we all know as the tire. Without the tire, driving would become a truly disagreeable experience. Moving 75 miles per hour down even the smoothest road surface, without tires, would just about rattle the teeth out of your head, as any of the Flintstone’s family would agree.

A properly functioning tire remains something rarely thought of while it is functional, but the slightest change can create many different problems for the driver. Tires hold their shape using a steel cage wrapped in rubber or another rubber-like compound. The thickness of the steel cable, or belts, used to maintain the integrity of the tire is nominal. The smallest pothole or chunk of ice can cause the steel belts to shift or even break, instigating an “out-of-round” situation for the tire. These cords maintain the round shape of the tire so any shift or break creates a circumstance akin to– if you can imagine– sitting on a fully inflated balloon. Obviously an out-of -round tire will feel like you’re driving over a small rock over and over, especially at highway speeds. Additional problems may also occur while driving on an out-of-round tire. Abnormal tire wear– excessive wear on either the inside or outside of the tire– can cause the vehicle to pull one way or the other and put undue stress on the suspension and steering systems. Needless to say, any one of these problems left unattended can easily mushroom into serious problems and costly repairs.

Tread depth represents another easily overlooked creator of expensive repairs. The average person will generally wait until all that remains of their tire is a nice smooth surface, possibly displaying steel cords in places. This is not good. A tire in this condition, referred to in Industry slang as a “may pop,” may actually blow at any moment. There is also a much larger chance of a steel belt breaking as discussed above. On any given tire, placed in between the tread blocks, lies a piece of protruding rubber called the wear indicator. Tire manufacturers place this indicator, usually 2 or 3/32nds of an inch above the point of being considered “bald,” first to give the owner some leeway from the time a new tire is needed to the time it is replaced. Secondly, tire manufacturers use different types of rubber and silica compounds to wrap the tire and this wear bar indicates the last layer of rubber before the steel cords start to show. Once a tire has reached the tread depth indicator the tire becomes very thin, making it much easier to pick up nails and increases the likelihood of blowout. A tire blowout on the highway can be bad news for anyone involved, including the vehicles around you.

Another much overlooked tire issue lies with a tire’s air pressure. Tire pressure set either too low or too high can wear your tires out prematurely and have major effects on the vehicle’s gas mileage. A tire with too low of air pressure will wear faster on the outside edges while too high of air pressure wears a tire in the middle of the tread. Air pressure set just right will wear the tire evenly all the way across. To find the right air pressure setting for your vehicle there is a sticker in the driver’s door jam with all the pertinent info on tire size and pressure, along with a great many other details about your vehicle. With the ridiculous rise in fuel costs lately a driver must use any possible way to cut down on fuel consumption. A tire set at too low an air pressure creates an undue load on the vehicle and can create a damaging effect on the vehicle’s gas mileage. Driving with a low tire, you can relate to driving through a mud bog wherever you drive, and the lower the tire the higher the fuel consumption. Tire pressure may be the simplest, which of course means the most overlooked, problem with any tire, so have your air pressure checked on a regular basis.

And so ends our reflection on tires, the great protector of the most influential invention in our great history, and on a side note, ourselves.