Every tire has a birth date—the day it was manufactured—and an expiration date that is six years from that manufacture date.Most automobile manufacturers warn drivers to replace vehicle tires after six years.The last two digits refer to the year the tire was produced, and the first two digits identify the week number within that year.
That tire was on a trailer that had been sitting in a field unused for 10 years, and it showed signs of dry-rot cracking.It is unclear whether trailer tires should be replaced every six years since they do not receive the same daily punishment as automobile tires.Expiration dates for tires manufactured before 2000 were based on a 10-year scale because the expected life-span of a tire was 10 years.Current guidance suggests that tires should be expected to last a maximum of only six years. A tire manufactured-date code, shown in the yellow box, may appear on the outside of some tires.DOT R5HG FHR 404 would indicate a tire manufactured in the 40th week of 1994 (or 1984, or '74).
If you find your "new" tires are more than two years old, feel free to request a newer manufacture date or a discount from the salesman. In case you were curious about other elements of the code, "DOT" means the tire has passed the Department of Transportation's testing requirements.The 11-character DOT code, shown in the red box, appears on the inside of tires.Recently, some tire manufacturers have begun to stamp partial codes on the outside of tires (facing away from the vehicle) so that checking the date does not necessitate removing the wheel.Tires are just about the most important part of your car.If they're in bad shape, the car's ability to accelerate, stop, and turn in all conditions is greatly compromised.Tires in hot dry climates have much shorter lives than those in moderate, moist climates.