Tire replacement question (good tread but some "dry rot")

1/16th inch? That's a good size crack. (Do you mean length or width? If it's width, get going!) I've driven on tires with 'dry rot' before, but the cracks were the width of a hair.

You don't know where you're moving? Get an all season tire and be happy. Oh, and bring the car to the dealer to have a look. They sell tires, but not as a main business, so they won't be as hard sell. They will tell you if they're safe.

I had to laugh...the Toyota dealership I worked at sold tires. They had a four tire stack each of four different sizes. If someone came in looking for tires, they were charged full retail price, and then the car was sent to the discount tire dealer down the street!

Hi, Thanks for your help! By 1/16 I mean depth. Well, they look more like wrinkles than cracks. They run the whole side of the tire (in a circle) so the length of the cracks/wrinkles is like a 14 inch circle. I remember they were there maybe a year ago though I can't remember if they are bigger now.

I read online that if a car is not driven much, then the special "oils" built into a tire do not get to the surface and dry rot is more prone to develop. Is this actually true? I'm curious if I'd put more miles on the Civic if the tires would actually be in _better_ shape now.

My '89 Corolla has 147k and had its tires replaced about 6 years/50k miles ago (good quality set from Costco) and are in much better shape than the 6 year old/44k mile tires on the Civic. Whether this is because the Corolla is driven more or b/c the quality of tires on the Corolla is much better or both, I don't know.

I can bring the car to Costco (where I would get tires for the Civic if I buy now) to ask the guys there what they think of the tires, though I don't know if they are experts in dry rot or not.

Just curious--how much profit did the Toyota dealer make on tires when you were working there? I met a guy who's in the rubber business, when I talked to him last year, he said wholesale prices for rubber and tires had spiked something like 80% with the increase in oil prices these past couple years.

Thanks again for your help, John

The minimum tread depth is 2/32." Passenger car tires usually have 10/32" or 11/32" when new, so the 5/16" on the tires is basically most or all of the original tread.

If the cracks in the sidewall are 1/16 (= 10/32) inch deep, then the tire is not safe to drive on, since the sidewall is much thinner than the tread. If you can see any fabric or metal through the cracks, the tire is unsafe.

If the cracks are superficial, then the tire is probably safe. I recommend that you have the tires looked at by a competent technician, preferably one that does not work for a place that sells tires.

In the future, some things that will slow down tire deterioration are staying away from electric motors and generators, i.e., refrigerators in garages, keeping the tire out of the direct sunlight, keeping the tires slightly over-inflated (4 or 5 PSI over the tire pressure listed on the car door also improves fuel mileage and tread life), and an occasional application of a rubber coating like ArmorAll.

the tires more than 6 years old and tires have an expected life of 6 years... after that its time to change no matter how many miles or tread left... i would think since it highway use, it more dangerous not to change your tires. if your crusing around town at 25-30 mph its no big deal when a tire fails... but 65 - 75 mph could make you loose your life.. the wrinkling is from shifting belts....i say change the tires...

troy

That's pretty deep! I'd be looking for new tires. In Mass, they won't pass inspection and you'll be forced to not drive the car.

I'd think it has more to do with the quality of the tire, but I had some incrdibly cheap tires on an old Grand Voyager that looked new after 4 years, and some newer, more expensive tires that looked horrible!

I heard a report on NPR a year or two ago, and then reinforced by one of the Evening News programs: With current tire materials and construction, 6 years is the MAX tire life. They recommended replacing 6 year old tires with new ones. It has something to do with the way the compunds break down over time.

I must agree with this assessment. I learned about tires the hard way, having a blowout while hauling a U-Haul trailer through the Arizona desert at 115 degrees. From that time forward, I've always looked at tires as the #1 priority, along with brakes and steering gear. If you blow up an engine or transmission, the only harm done is that you're stranded on the road and your wallet will be in pain, but blow a tire and your life could end in the next few seconds. Think hard and well about tires.

Hi everyone, Thanks again for your help. I scrutinized the tires after work today and it looks like I overestimated the size of the cracks. They are more like hairline cracks and definitely not 1/16. That being said, I'll go get them inspected by a professional and go with his recommendations.

Thanks, John

Well, you make it sound like a tire blowout is such a risky thing while it really isn't I live in Arizona and in summer I see blown tires ALL over the place and no wrecks from it. It's really what the driver does after the blowout that decides his fate. If you slam on the brakes or jerk the steering wheel then you could cause the crash yourself. stay calm, let it coast and slowly come to a halt is the best thing to do.

I second the 4 to 5 psi inflation over suggested pressure. I get MUCH better life out of tires. downsides (if you consider it) is that the ride is a tiny bit harsher and some tires are more noisy this way. Worth it to me.