Old tires are especially dangerous in hot climates like Florida. Over time the material properties of rubber break down and the rubber in tires loses its supple and elastic qualities, making it more subject to failure. Consider an old, brittle rubber band which loses its elasticity and breaks easily. While the notion that an old tire is dangerous may be a concept which can be appreciated, it is far from obvious to always know when one is dealing with an old tire. Tires which are stored in spare wheel positions for long periods of time may be chronologically old but look brand new and have deep unused tread depth.
The age of a tire is identified in the DOT number which appears on every tire. Without special knowledge, the DOT number resembles a cryptic series of letters and numbers. Determining the age of a tire is further compounded by the fact that the DOT number is difficult to locate and see because it is molded on the tire in the same color as the rest of the tire, and situated on the area of the tire that sits next to the rim.
We recently handled a case involving a brilliant young man (valedictorian of his high school class, scholar athlete award, most likely to succeed award, degree from an Ivy League college in biomedical engineering) who suffered a traumatic brain injury as a result of a rollover accident caused by a defective tire. The tire was a nine year old tire which was in the spare position for 8 and ½ years before ever being used on the roadway. It looked brand new with deep, pristine tread when it was placed on the right rear wheel position by a local tire service dealer. After the accident an investigating Florida Highway Patrol officer was assigned to examine and photograph all of the tires. Even the highly trained Florida Highway Patrol officer had no idea how to read the DOT number or determine the chronological age or birth date of the tire. Our theories in this case against the tire manufacturer included various tire defects, and failure to warn about the age of the tire.
A general rule of thumb adopted by many tire experts is that a tire should not be used beyond six years after the manufacturing date. When you purchase new tires insist that the DOT number reflect a date of manufacture within twelve months of the date of purchase, because unused does not equal new.
At Jay Halpern and Associates we have handled numerous tire defect cases based on the tire aging theory, and failure to warn. Tire cases are a form of product liability cases. In tread separation and rollover cases it is also important to consider other automotive product defects. For this reason we typically investigate seat belts, air bags, roof crush and other crashworthiness issues in tire failure cases that result in a rollover.