Making sure your tires are properly inflated is not only important for efficiency and gas mileage, but is necessary to ensure the safety of you and your family. A recent study by the National Highway Traffic Safety Administration (NHTSA) determined that vehicles with tires that were under-inflated by at least twenty five percent were three times more likely to be involved in a tire-related car accident.1 There are also the risks of overheating, failure, and at the very least adverse effects of handling and tread life.
Another dangerous result of under-inflated tires is that it causes longer stopping distances. Alertness is an obvious factor to reaction time when driving, but even with the highest level of reaction time, if your tires are under-inflated, it can cause a hazard for you and other drivers around you. Tire failures cause an estimated 11,000 crashes a year.[1]
There is also an increased amount of stress put on the other components of the tire, which could be at a higher risk of failure. When a tire is used while under-inflated, the sidewalls flex and there is an increase in the air temperature in the tire.[2] This alone increases the risk of failure. There is also more pressure added to the shoulders of the tire, which affects the tread life of the tire. This causes tires to age on average 32% faster than those that are properly inflated.
Weight is distributed differently because there is more tire surface on the ground. This increase in tire surface is also given credit for the loss in gas mileage, and decrease in maneuverability.[3] The rolling resistance of an underinflated tire on a wet surface is greater than that of a properly inflated tire. When what the NHTSA calls the “footprint” of the tire is larger because of under-inflation, it affects the stopping distance as well as increasing the risk of sliding on wet roads.[4]
Tire pressure monitoring systems have been required by a U.S. government mandate in all cars produced after 2008. This lets drivers know when their pressure is 25% or more below the recommended level of inflation.[5] It would be a mistake for consumers to always rely on this device. Keeping a constant awareness of tire pressure keeps risks low.
With advancing technology and increasing consumer awareness, studies still show that 26% of average drivers have at least one tire that is under-inflated. With this high of statistical unawareness, it is no surprise that there is continuing litigation on the subject of tire failure.
Written by:
Lyndsey Mott
Approved by Francisco Guerra, IV
Watts Guerra LLP
4 Dominion Drive, Bldg 3, Suite 100
San Antonio, Texas 78257
Phone (210) 447-0500
© Watts Guerra LLP 2015
[1] Liza Barth, NHTSA Study Finds Underinflated and Worn Tires Increase The Likelihood of a Crash, Consumer Reports (May 15, 2012) http://www.consumerreports.org/cro/news/2012/05/nhtsa-study-finds-underinflated-and-worn-tires-increase-the-likelihood-of-a-crash/index.htm.
[2] 41,829 NHTSA ISSUES FINAL TIRE PRESSURE MONITORING RULE, 2009 WL 3622717
[3] The Aerospace Corporation, Evaluation of Techniques for Reducing In-use Automotive Fuel Consumption, June 1978.
[4] For example, the VRTC only tested new tires, not worn tires that are more typical of the tires on most vehicles. In addition, the NHTSA track surface is considered to be aggressive in that it allows for maximum friction with tire surfaces. It is more representative of a new road surface than the worn surfaces experienced by the vast majority of road traffic. The previous Goodyear tests on wet surfaces were conducted on surfaces with .05 inch of standing water. This is more than would typically be encountered under normal wet road driving conditions. The agency expressed concerns with the adequacy of both sets of test data in a memo to the docket. (Docket No. NHTSA-2000-8572-81.)
[5] Shane McGlaun, Study Says Vehicles With Underinflated Tires Three Times More Likely To Be In An Accident, Detroit News, (May 14, 2012) http://www.dailytech.com/Study+Says+Vehicles+With+Underinflated+Tires+Three+Times+More+Likely+To+Be+In+An+Accident/article24674.htm
