my opinion here based on actual tire knowledge, and NOT biased by profits....
replacing perfectly good tires simply because of the expiration date is a personal preference...
prior to the year 2000, tires had a 10year expiration date, but tire technology hasnt gotten worse since 2000, so why did they change the expiration it to 6 years?.... the answer is mostly for marketing purposes, shortening their liability time, and using "safety" as their excuse for changing it....
the statement that the tires need to be replaced after the expiration date is a "blanket coverage" statement that is taught, because the manufactures and OEM dont know how the tires have been used or where, or how much, so rather than detail it out year by year and all the various ways the tire may have been used or will be used, and what to look for, they just put a 6 year expiration date on them....
tire expiration dates are no different than the expiration dates on other products that we consume (and eat)... just because the expiration date has arrived, doesnt mean it has to be discarded, but it means the product is "best used" before this date.
a tire that has never been on the ground and never seen direct sunlight has very little degradation in 10 years.... the effects of increased ozone can cause the rubber to dry out, just like the uv rays do, but the uv also causes some erosion of the rubber... but usually, if the tire doesnt have "age" check marks in it, its most likely safe to run...
as the check marks begin in the rubber, it allows more of the rubber to be exposed to the elements, and sometimes even allowing the elements to get into the belts, which is bad for the tire....
im NOT suggesting that you use a tire that is past the date anymore than I would suggest to you what brand/model of tire you should replace it with, but I am telling you its a personal preference... and that I dont replace tires until I see they are checked, road damaged, or worn down close to the wear bars, and Ive never had any issues.... even after ten years, and I own 5 trailers (different types for different purposes) that some of them have 15year old tires on them, and still going strong....
I do agree that tires can NOT go forever just because they have good tread and have no check marks in them, but I am saying that 6 years is an unreasonably short life expectancy for tires...
and you can bet that when the tire store removes a perfectly good tire, it wont be discarded just because the date is expired, but they will sell it as a good used tire to someone else... and if its good enough for someone else to run, its good enough for me, which over time saves me lots of money..... BUT, I wont buy a used tire because I dont know how its been taken care of or how long it sat in storage since it was taken off, or where it was stored.
I do believe in safety, which is why I check my tires often, but for those who could care less about getting longevity from the tire, or the acute safety issues of them, they should just pay the money for new tires and be done with it... but installing "new tires" STILL doesnt insure that one of the new tires wont develop an issue, either because it has a hidden fault or from a road hazard, before the expiration date ever arrives.... in which case you would have to install your "expired" spare tire so you could continue on your journey.
the tire vinyl covers that some people use to cover their tires with when set up for longer periods arent just for looks, but they do help preserve the tire from UV degradation and slows down the inherent checking that is caused by exposure...
think of the expiration date on the tire as a "recommendation", and not a hard fast rule, and then do what you think works best for your time and budget...
