Very old tires a problem?
 

My '81 GS, a 60K mile mint all original car, of which I am the original owner, has been retired to the car show circuit, meaning it goes from a few to maybe 50 miles a month to local shows and Friday night gatherings. I have a set of Carroll Shelby Minilite-replica alloy wheels which I bought when the car was a few months old and 205/60-13 Sumitomo tires which were mounted I believe in 1992. The tires have maybe 5000 miles on them. I had the front tires balanced today to eliminate some steering wheel shimmy and the tire/aftermarket wheel shop I took them to told me I was "absolutely crazy" to be driving around on 15 year old tires even though there is no dry rot, they look fine, and the mileage is low. He says they deteriorate over the years from the inside and could come apart suddenly without any warning signs. Any truth to this? This is not what I wanted to hear considering I still like to hang the tail out a bit once in a while on exit ramps like I've done for 26 years. The old Sumitomos, which never had great grip to begin with, have lost the handle a bit from age over the years, but seem to be fine otherwise.

I'm no expert, but I think you'd be fine as long as you don't push the car to it's limit. Why not invest in a new set anyways? Sumitomo tires are very reasonably priced. I just ordered a set of Cooper cobra radial g/t's for mine last week, they were around $60 a tire.

Every situation is different, but I bought my 80 in January of this year and the tires looked pretty old but had good tread. I intended on making them last for a while, but now that I fixed my cooling issue I decided to run it up a bit-I lost a chunk of one and another was showing cords after a small amount of spirited driving. The tires looked OK but with all the heat in the tires they just started coming apart. They were cheap to begin with and I'm not saying this would happen but old is old and I would hate to lose a SA or FB because of some stupid tire. Just got some Toyo Spectrums, OWNS Sumitomo, I've owned them both, same size

Regarding old tires:

I purchased a 1961 ice cream truck in 1997. It was in a garage for 15 years, dirt floor. I restored it and sold ice cream on the streets for 3 years and sold it in 2005. The tires were not changed and they performed well.

So for your situation, on shows etc, I'd say you are fine. But I would not hang the tail out too often.

a guy i worked with had a widebody and modded 79 camero he drove to work every once in a while. the tires on that thing were old, i cant remember how old though. ten to fifteen years i think. one day he was leaving work and had a couple interns riding with him that were ford fans. so he decided to show off a little bit. he tried to get a little sideways coming out of the road and ended up going off the road and into a ditch. he smashed up his widebody kit, damaged his enkeis, and killed a tire.

moral: dont drive old tires like theyre new tires. his just couldnt grip cause the rubber was so hard.

Old tyres
 

I think that's the point really. If the tread is fine they'll perform alright (even in the wet). But as rubber gets old it doesn't deal with changes in temperature as well as new rubber, so you'll find the tyres don't soften up and will still be hard when you corner (reducing grip). And when they die they'll probably die spectacularly with chunks of rubber falling off (from what I've heard).

Thanks, all, for the replies. I think I'll keep the old Sumis for a while and take it easy. If it was a daily driver I'd replace them for sure.

jvg! Original owner of a "cherry 81 GS" with 60k miles. Could you find one like that today? How much would it cost to replace? A set of 205-60-13's are "very reasonable." Not to mention the improvement in tire technology the past 15yrs. My 2cent's.

^ good points, if it sees and highway speeds replace them.

Old tires get hard with age as the volitiles evaporate out of the rubber. They ride harder, have less grip, less flex and eventually become dangerous. A hard tire can fail with little warning. At highway speeds, this can be quite dangerous. Personally, I would replace them purely for safety issues.

I recently replaced tires that were only 3-4 years old. They still had 50% tread left, and even less grip remaining. A golf cart could out handle my car on those old tires. Ok, maybe I'm getting slightly carried away, but just barely.
The old tires were fantastic when I got the car, and really held the road good. 2 years later, I was having so much trouble getting the car to at the AutoX, I actually "Upgraded" to stock rims and 205/60-13's with a very high treadwear rating. I woulda never expected S speed rated 13's to outhandle V rated 15's, let alone that badly.
New 205/50-15's made just as much of an improvement over the 13's, as they had over the older 15's.
It's your car, and your life. Are either one worth less than a set of new tires?