Why so many blowouts?

[Carm]

I see a lot of posts on this site about blowouts... Is it due to extreme heat? Exposure to sun? Speed? Low tire pressure? A combination?

The majority of posts seem to be from southern areas where it's typically much warmer, with a lot more sun. I live in a coastal rain-forest in BC: things that aren't covered up turn green in a hurry. I don't get much sun - it's usually overcast or raining and temperatures stay low through most of the year.

In over 40 years of driving I've never had a blowout and I don't know anyone who has. I've had punctures and I've popped tires and wrecked rims due to hitting stuff in the road but I've never had a tire blow for no apparent reason.

When we travel we head north. We've done thousands of miles in Alaska, Yukon and Northwest Territories and northern BC and Alberta, much of it on what I would call primitive gravel roads that will rattle your teeth out. I've had overhead cabinets fall off the ceiling on the way to Telegraph Creek and once in my old Itasca had the ignition key and cylinder rattle out of the dash and hit me in the foot while I was driving. Heading to Fort Simpson a few years ago we had the front wheels airborne several times hitting frost-heaves at speed which has got to be tough on tires, but I've never had a blowout.

So what is it that causes blowouts? The only thing I can think of is the cumulative effects on the tire of extreme temperatures over long periods, and long exposure to the sun.

Am I delusional? Am I just lucky?

[Snomas]

We never have had a blow out. Change tires @ 6 yrs. Check them all the time. Added TPMS system last year. I had a tire go flat parked camping one year. It was a valve extension gone bad. Don't use that brand any more!! I have 92k miles on my Dutch star. Only have used Michelins and on my 3rd set.

[jwmII]

The number of blowouts compared to the number of tires in service is miniscule. What gets all the attention regarding blowouts is the potentially devastating results frequently caused by blowouts.

[Pogoil]

Many who travel in motorhomes and trailers do not even think about their tires. Some never check pressure unless they look low.
I was taught early when getting my CDL. Check tires, lugs and wheels daily or at each stop.

About a week ago in an RV park I was helping a guy park and noticed his trailer about 10-12 years old. As he was pulling forward the at the bottom of the tires with every rotation cracks would appear. I told him about them and he could care less. Sure they were on the trailer when he took delivery. Give tires the respect and most times they will last.

BTW. had my second blow out in 40 years and a couple million of miles driven the other day. You guessed it I was driving a trailer of a friends for him and the tires were 10 years old and neglected.

Pogoil.

Pogoil.

[2gypsies1]

JimM68 wrote:
Maybe.
Blowouts are caused by overloading or low inflation, and also by just plain old tires.

Bad luck can play a pretty big role too.

This is the reason.

[creeper]

Then of course the assume the tires are being used frequently. Sitting for long periods has it's own set of problems.

[Kayteg1]

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=267

The 6-7 years tire life expectancy was old rule for passenger car tires.
Bare in mind car tires have about 1/8" sidewall, while 22.5" tires over 1/2" (although I did not see RV series tires)
At present time each manufacturer has different recommendation, while most of them oscillate about 10 years with annual inspection after 6.
The best IMHO is Continental

Continental wrote:
Since service conditions vary widely, accurately predicting the service life
of any specific tire in chronological time is not possible.

[creeper]

I doubt low tire pressure is much of problem. Most people I know inflate to max pressure to let's say 100PSI which is a common max pressure.

Tire heats up and it's not 115-120psi, now you end up driving in the south and it's Africa hot and the tires are now 130psi or more. Now throw in tires that have not been cared for their entire life. Not a good combo.

How many people put a water based UV inhibitor on their tires?

I suspect you'll find that age, combined with max tire inflation and overweight to be a big cause. LOTS of overweight coaches rolling around. I notice that most people who post in various forums about a blow out also show the tire is over 5 years old.

Tires can last longer then 5 years with actual use and actual use is better for the tires, but these things sit so often and long.

[Pattwood]

OEM tire producers recommend changing tires 7 years after production. This is due to cumulative effect of UV exposure. Recent studies are suggesting that this time interval be changed to 6 years. UV exposure varies across the continent with southern regions clearly being higher exposure.

Clearly, other factors (temperature, loading, road conditions) all contribute, but the breakdown of sidewalls is a UV phenomenon.

[wa8yxm]

JimM68 wrote:
Maybe.
Blowouts are caused by overloading or low inflation, and also by just plain old tires.

Bad luck can play a pretty big role too.

A very good reply.
Low pressure (or high pressure) either one can cause shortened tire life and a blow out. Some folks inflate to one of the following pressures. (note these are examples and yours likely WILL be different)

Molded in the tire is ....... Maximum pressure of 80 PSI
So they go 80 PSI (The full sentence is Maximum load of XXXX at Maximum pressure of 80 PSI)

Some read the sticker inside the RV and it says "Tire pressure 60 PSI" so they blow it up to 60.

Some: Well the tire store always puts in 70 PSI.

A few folks run the RV across a scale twice and go to the tire maker's web site" THis wheel is carrying WWWW Pounds so it needs XX PSI,m< This wheel has YYY Pounds so it needs ZZ PSI and so on. (The right way to do it) They also may add a few PSI for safety (I have no problem with that).

Another problem is overloading the RV

Some RV makers use small wheels that spin very fast,, They recommend a max towing speed of 45MPH Of course we drive 70. This means the bearings are spinning faster, MORE HEAT and KABOOM.

Some folks look at a 15 year old tire and say "Tread's still good, I don';t see any cracking" and BOOM... IT blows 1 hour later.

And as the person I quoted said: Some folks... Well if not for BAD LUCK they'd not have any luck at all.. IE: 4x3 lying in the road (Yup, Been there all right).

[DanTheRVMan]

Actually, the OP is correct. High Temperatures in the south is a major cause of degradation to all polymeric materials including tires.

But many of the posts about inflation and other issues also play a role in blow outs so being in the north west does not mean you are home free and can ignore your tires.

[Kayteg1]

Per my observations commercial tires, even when rated for low speed can take higher speed just fine.
In the years when diesel cost 99 cents or less, I had seen several times semi-trucks "growing" in my rear view mirror, when I had 90 mph on my speedo and then vanishing in front of me.
Even today on 75 mph I-80 in Nebraska lot of trucks make 80+

[Jagtech]

I'm actually surprised that there aren't more tire failures reported due to excessive speed. We've all seen it... a huge rig passes us when we're travelling at highway speeds, and one has to question if their tires are actually rated for anything above, say, 65 MPH. Admittedly, some tires are speed rated higher, but why push the limits? Higher speed means higher forces on sidewalls, higher temperatures, less time to react if there's a problem with a tire, and more damage when it blows.

[Kayteg1]

There is a reason why pressure monitoring system become mandatory on US sold cars quite few years ago.
Recommend pressure is always a balance between riding comfort, tread wear and rolling resistance (fuel consumption).
Could you handle the discomfort, the max psi allowed is the best for 2 other parameters. Radial tires will not change the shape with high inflation.
I had 2 blow ups on my vehicles and several more on equipment trailer.
When I blame vehicle blow ups to aging rubber, the low ride trailer had tire size where good quality tires are not available.
Cheap tires with heavy load don't need much.

[Dutch_12078]

frankdamp wrote:
There's also the possibility of over-inflation being the cause. So many people seem to think that the "correct" inflation pressure is the number molded into the text on the side of the tire, regardless of the actual load being carried, rather than getting their rig 4-corner weighed and inflating to the manufacturer's recommendation.

Over-inflation results in the tire having a curved profile at the road surface, with the center of the tread taking more of the load.

Also, the term "blow out" suggests an explosive failure, not a simple loss of pressure.

The pressure listed on the sidewall is the maximum cold inflation pressure. That's the psi at which the tire will hold its maximum weight rating. A healthy tire should never fail when inflated to that pressure. If a vehicle is at or near that weight, then that's the pressure that should be used for inflation.