QuestionI just bought 4 new tires from a dealership that "cut me a deal" and after I drove away I checked the DOT and there were 2 tires that were 1 year old and 2 were 2 years old. I brought it back and insisted that they replace those two with newer DOT tires. They are 225/70/R16 UniRoyal Laredo AWP's. The "replacement" tires put on today only has a DOT on ONE sidewall (the one facing in, of course) it either says 0107 or 0101... I can't tell. I'm going to bring it to another dealership to decipher.
An expert over at Toyo told me he would not put on tires that are 2 years old on his own vehicle. The folks at UniRoyal said that the industry standard is 6 years - UniRoyal's sounded like a textbook answer to me.
So I have 3 questions:
a) As of 2007 did UniRoyal start putting their DOT's on only ONE sidewall?
b) Since rubber is a natural product, how fast does it actually deteriorate, even when stored in optimum conditions?
c) Am I just being a lunatic for wanting tires that have been recently manufactured?
AnswerLisa,
It has been standard industry practice to put the DOT number on one sidewall, typically the bottom half of the mold - which usually resulted in this side being inboard on the vehicle. However, NHTSA (National Highway and Traffic Safety Administration) has mandated a change in location so the number appears on "the side intended out". If I remember correctly, this change is a "phase in" (meaning every year a certain percentage of tires sold have to be this way) and that is supposed to be complete by 2009.
But properly stored, tires don't change much over time and certainly tires that are 3 years after manufacture are OK and I would have no reservations about using them. The key to this is "properly stored". Tire manufacturers' warehouses have good storage conditions, but I worry about some wholesalers and retailers. This is probably where the "Toyo Guy" was coming from.
The "6 year" is an assesment of when a tire should be removed from service regardless of how much wear it has. There is some....ah.....oh..... let's call it a disagreement. Everyone in the industry agrees that there is a time limit on exposure, but the factors that accelerate this vary widely - heat being a major factor.
I've taken the position that if one lives in AZ, NM, TX, NV, CA, or FL, a properly cared for tire should be removed at 6 years, and if you live in a northern state - let's say MI, MT, or ND - the limit is 10 years - and other states are in between depending on how far north they are.
This is for a "properly cared for" tire. ANY tire, if subjected to abuse, will "age" more rapidly and it can not be predicted accurately. "Abuse" means underinflation, overloading, exposure to ozone, heat, or light (UV especially).
So if you check your pressures once a month like you are supposed to, then you shouldn't worry much about a tire's age.
