I would stay away from them. They are at their limit time wise. It doesnt mean they are not good. If they have been stored out of the sunlight. they may be ok, but why take a chance.
If your other 3 tires are within about 3 years of needing to be replaced, then you'd probably be just fine replacing one with the older (but unused) Uniroyal you found online for a great price assuming it's an exact size match. Just be sure that if your other 3 tires are all-season (M+S rated, on tire) that the replacement tire is also all-season and not a summer tire. Summer-only tires perform very poorly in the cold or light snow, far worse than an all-season tire does. You don't want to ruin your car's traction balance in the cold or snow.
When the other 3 tires need to be replaced within the next 3 years though, I'd definitely replace all 4 tires including the older Uniroyal even if it still looks okay.
If you expect more than 2-3 years of service out of the replacement tire, I'd recommend spending the extra money on a tire that isn't already four and a half years old.
7 years seems to be about the typical life for a typical tire under typical conditions.
Is this one you found online the same model and size as the other 3? How old are the other 3 and how many miles on em? If they are not that old I would consider buying a new one so everything was closer matched. IF that model is no longer current then getting the one online may be the next best option.
If the online one does not match then you are far from ideal anyway so the age is not likely going to be the worst aspect of your plan.
The five year old Uniroyal will more than likely still have it's integrity if it has been stored properly. However, Uniroyal is an entry level quality tire brand. For more than likely just a few bucks more you could purchase a new tire of equal or better quality that would not have the risks involved with buying a 5 year old average quality tire.
If its been stored inside, I wouldn't be afraid of it. I'm a farmer and have close to a hundred tires on the ground. A lot of them are used tires on machinery and trailers that I use until they won't go any more. You would be surprised how long a tire will run. This one being new and only 4 1/2 years old should be good to go. Take it to a place that mounts tires and have them look it over. Push down on the bead and tread and see if its weather checked. If it is ,don't buy it.
In older tires the rubber breaks down and allows the tire to come apart, if you don't have much experience behind the wheel I would stay away from those tires. A blow out wouldn't make me crash but I've been driving for 34yrs. If the tires are too old Firestone won't even mount them
no don't buy it. every tire has a fixed number of years used or not and anything over 2 years is not worth buying.
If there are no weather-checks on the sidewalls they should be OK.
I found a Uniroyal tire online at a great price, but the DOT is 0510 which is the 5th week of 2010. I need to change out only 1 tire. Thanks.
