Most of the 2008 model year vehicles are equipped with TPMS or Tire Pressure Monitoring Systems. This technology is very convenient to use since it simply illuminate an on-dash warning light whenever the pressure in one or more tires is low. However, North America’s largest motoring and leisure travel organization, AAA believes that TPMS should never be made to replace monthly tire pressure checks.

All 2008 model year vehicles and other newer vehicles are equipped with a tire pressure monitoring system as mandate by the federal law. Unfortunately the TPMS is not 100 percent reliable in the sense that on-dash warning light only illuminates when a tire is at least 25 percent under inflated which according to AAA is way below the pressure required for safe driving.

Basing on a recent survey conducted by Rubber Manufacturers Association, at least 40 percent of motorists said that if their vehicle is equipped with a tire pressure monitoring system they would only check their car’s tires only if the dashboard warning light came on. If there is no warning light then they would not check their tires. Also more than two-thirds said that since their vehicle had a TPMS they have become less concerned with routinely maintaining their tires.

Why is proper tire pressure important?
Correct tire pressures are vital to efficient and safe vehicle operation. And according to the research conducted by AAA one in every three cars has under-inflated tire. Furthermore, National Highway Traffic Safety Administration has also reported that around 660 fatalities and 33,000 injuries have been attributed to low tire pressure-related crashes.

Here are some of the reasons why it is not advisable to drive with under-inflated tires:

1.    It is unsafe to drive with under inflated tires since they tend to build excessive heat that damages the tires leading to failure. It can also affect handling precision and increase stopping distances.
2.    For those who want to save on their fuel consumption, do you know that for every one PSI pressure drop in all four tires, gas mileage is reduced by around 0.4 percent?
3.     Under-inflated tires wear tires unevenly reducing the life of the tire thus requiring for more frequent tire replacement.

Now that you know the importance of maintaining correct tire pressures, the next thing that you should be aware of are the types of technologies that monitors tire pressure. There are two types of tire pressure monitoring systems that are currently used on new vehicles: the direct and indirect sensing.

The direct sensing systems are the most accurate and advisable for use. This type of system makes use of a sensor found inside each tire that detects the pressure up to one pound per square inch (PSI). Most direct-sensing TPMS can read out tire pressures on a dash display thus eliminating the need for the traditional gauge that checks tire pressures. But still it is very important for car owners to consult the tire information decal or owner’s manual of their vehicle to know the correct tire pressures that their car’s should have. AAA also recommends for motorists with cars equipped with direct sensing TPMS to check on-dash readout monthly for any decreased pressure.

On the other hand, indirect sensing systems do not monitor the actual pressure in each tire and are less sensitive as compared to direct sensing systems. But indirect sensing TPMS can monitor the anti-lock brake system wheel speed sensors to determine when one tire is under inflated as compared to the rest of the tires. An under-inflated tire usually has a lower profile and rotates faster than a properly inflated tire. And just like the direct sensing systems, the indirect sensing systems will not also illuminate the tire pressure warning light until one tire is under inflated by 25 percent. However, since indirect-sensing TPMS monitor relative tire speed rather than absolute tire pressure, it usually fails to detect low tire pressures in case all four wheels deflate equally. This is also the very reason why AAA still recommends the use of a gauge to check tire pressures monthly to check under inflated tires.

And since the winter months are here it is important for car owners to check their tire pressures since tires lose one or two PSI for every 10 degree drop in outside air temperature.  For more information on TPMS or how to properly check their car’s tire pressure they may visit any local AAA Approval Auto Repair facility for assistance across North America. To locate an AAA facility in your area simply visit AAA web site at www.AAA.com.