K02 Tire blew up causing body damage ... need a wheel for a 2004 Land Cruiser ...

[Bisho]

That is the experience, but scientifically, at low pressures the plies will rub one another (relative motion between plies) wearing the plies making it weak and eventually burst open. This won't happen to a tire with low number of plies. Any tire with 10 or more plies should run no lower than 40 PSI, this ensures all plies act like a thick wall and one unit. I do have 10 plies and first set in my life.. I hate 40 PSI but got to live with it until I switch back to 6 ply LT tires. Thanks for sharing your experience.

Do you have some documentation to support this? Asking @dbleon to show the goods, but not showing the goods yourself is a bit disingenuous. The experience @dbleon and I (and many others I know) have doesn't support it, but I realize we aren't tire manufacturers and we aren't running scientific studies. I looked all over the internet and found a lot of conflicting info, but it was all platitudes and no data. Why do 10 plys have rubbing issues, but 3 plys don't? I have other vehicles in the same weight class that came from the factory with LT tires that only call for 35 psi, why are they ok?

BTW, I'm not in attack mode, but we are all sometimes blind to the old wives tales we choose to spread as gospel.

 

[cwmoser]

Yes, I too would like to read something from BF Goodrich about Tire Pressures with KO2's.

 

[gnob]

Do you have some documentation to support this? Asking @dbleon to show the goods, but not showing the goods yourself is a bit disingenuous. The experience @dbleon and I (and many others I know) have doesn't support it, but I realize we aren't tire manufacturers and we aren't running scientific studies. I looked all over the internet and found a lot of conflicting info, but it was all platitudes and no data. Why do 10 plys have rubbing issues, but 3 plys don't? I have other vehicles in the same weight class that came from the factory with LT tires that only call for 35 psi, why are they ok?

BTW, I'm not in attack mode, but we are all sometimes blind to the old wives tales we choose to spread as gospel.

exactly.
tire pressure recs are based on the tire size and expected load. period. straight from a tire manufacturer.
i basically NEVER ran my 37s over 40psi. i repeat. never. in fact i ran then at speed at under 20 psi for weeks. they are absolutely fine and wore fine the entire time i had them.
more than happy to email this document if your google-fu is weak.

 

[Kabanstva]

Yeah I also want more scientific data behind not running 10-ply under 40psi. So far it’s just “trust me bro”. I’m not seeing anything believable.

 

[Kabanstva]

OP did you have any issues with your K02s when you originally bought them and had them mounted and balanced? Between my 80 and 100 I’ve bought over two sets of K02s (10-ply). All balanced out fine but one tire. I had the tires shipped to a Lexus dealer and they couldn’t get one tire to balance, I had to make a claim with tire rack and had the tire replaced. Not sure what the issue with it was.

 

[Jack90210]

I checked the Tire Pressure in the remaining three KO2's and they were all right at 32psi.

ALSO, the usage was mostly Highway Driving. Rarely offroad and then visiting construction sites.
And the last time off of pavement was several months ago.

Jeez man, that is WAY TOO LOW for any LT tire on a Hundy regardless of tire size.

Highway driving is the worst for an underinflated tire because heat builds much more quickly at speed due to the amount of energy that goes into flexing the tire.

Underinflation is how your tire was destroyed.

 

[Jack90210]

The .. “must be 40 or higher” is just too broad of a statement IMO based on personal experiences. Have run multiple sets at 35 ish up through the mile warranties with no problems.

But .. meh you do you

Thanks!

No, it isn't. That's factually false.

Depending on the size of the tire, that's either slightly underinflated or substantially underinflated.

For this example I've chosen a 285/65R17 since it's the smallest common size for those running RW wheels. Larger tires will require even more pressure than the 39psi in this example.

Note that 39psi is the inflation necessary merely to give the LT-rated tire the equivalent load rating to a P-rated tire. To surpass this rating, a higher inflation pressure is necessary.

 

[Jack90210]

Yeah I also want more scientific data behind not running 10-ply under 40psi. So far it’s just “trust me bro”. I’m not seeing anything believable.

Here you go. I would read the PDF in this link (that I've posted half a dozen times elsewhere on Mud):

StackPath

Please note that size-for-size; LT-metric tires require higher air pressure to carry equivalent loads of P-metric tires, and that any failure to adjust air pressures to achieve the vehicle’s load requirement will result in tire fatigue and eventual tire failure due to excessive heat build-up.

 

[Jack90210]

Screenshots from the doc showing the heat increase from underinflation attached.

 

[dbleon]

122F is the ambient temperature here during the summer

 

[Jack90210]

122F is the ambient temperature here during the summer

This is the wrong takeaway from the data.

 

[Bisho]

I can’t help but think of two things in this discussion: “a little bit of knowledge is a dangerous thing” and “lies, damn lies, and statistics.”

There are two documents here from the same manufacturer (Toyo) that appear to say different things, and each of us is potentially cherry picking which one to believe.

The weight a tire can support is only one of the factors that goes into an OEM decision tree when picking a tire and recommended inflation, otherwise all the tires would be the same. Handling, stopping, ride, etc. my F-350 actually has a range of recommendations based on gross weight.

The first document shows how much inflation you need to support a given weight. Our trucks all need to support less than 2000 lbs per tire, and Toyo says you can do that with 30psi in all tire sizes.

The second Toyo document would seem to contradict the first, but only if you assume the only reason Toyota recommended tire pressures based solely on weight capacity, and ignore all other factors. The reality is the tire pressures Toyota call out allow those tires to carry far more weight than the truck is designed for (~9000+lb?). So I’m assuming Toyota pressure specs were based on other factors I don’t know.

I do know from my personal testing, over 150k miles, that lower pressures (33psi) have had no adverse impact on wear or fuel mileage, but sure improve the ride. Take that for what it’s worth and do what you think is right, but be careful casting stones when others choose differently.

 

[hoser]

Here's my take:

32psi may have contributed but it's not that low to bring the tire carcass over 200 degrees.

"Most experts consider 195 degrees Fahrenheit as the “line in the sand” when it comes to tire temperature: Beyond that point, the temperature will start impacting tire life. At 250 degrees, a tire will start to lose structural strength, could begin experiencing tread reversion and the tire will begin to lose strength."

I'd say the tire deteriorated over an extended period of time and that is why the carcass blew out so evenly. There needs to be another contributing factor. What generates heat? Brakes. And I've seen slightly stuck calipers translate to over 300 degrees measured at the hub.

Quick search says cwmoser had a stuck brake caliper issue spanning years? along with pulling a trailer. How does that sound @cwmoser ?

If you pull that brake rotor and check the bearings and the grease for excessive heat, that would give supporting evidence. Compare it to the other side.

 

[MongooseGA]

Here's my take:

32psi may have contributed but it's not that low to bring the tire carcass over 200 degrees.

"Most experts consider 195 degrees Fahrenheit as the “line in the sand” when it comes to tire temperature: Beyond that point, the temperature will start impacting tire life. At 250 degrees, a tire will start to lose structural strength, could begin experiencing tread reversion and the tire will begin to lose strength."

I'd say the tire deteriorated over an extended period of time and that is why the carcass blew out so evenly. There needs to be another contributing factor. What generates heat? Brakes. And I've seen slightly stuck calipers translate to over 300 degrees measured at the hub.

Quick search says cwmoser had a stuck brake caliper issue spanning years? along with pulling a trailer. How does that sound @cwmoser ?

If you pull that brake rotor and check the bearings and the grease for excessive heat, that would give supporting evidence. Compare it to the other side.

To me, this seems more plausible than simply running the tire at 32psi for an extended period of time. If it was the pressure, I imagine we'd see similar signs to the failed tire. It's either a factory defect, or something in line with what you're suggesting here.

 

[hoser]

The second Toyo document would seem to contradict the first, but only if you assume the only reason Toyota recommended tire pressures based solely on weight capacity, and ignore all other factors. The reality is the tire pressures Toyota call out allow those tires to carry far more weight than the truck is designed for (~9000+lb?). So I’m assuming Toyota pressure specs were based on other factors I don’t know.

They are not saying 9k lbs. They are saying 2117 lbs x 4 = 8468 lbs.

Curb Weight is approximately 5400 lbs. GVWR = 6856 lbs. Payload= 1456 lbs

They are conservative because one could theoretically put almost all that 1456 lbs over one axle. The weight balance of the 100 is near 50/50 so 5400/2=2700 lbs. Add 1456 lbs and you get 4156 lbs. Two tires at 2117 x 2 = 4,234 lbs... so right about there.

 

[NE Snowman]

I've never had KO2s but my 2500 cargo has E loads and the fleet mechanic that services it always sets my fronts to 65 and rears to 80, door specs are 65 and 80 as well. Curb weight is 5300, I'd bet we have at least a 1500lbs of tools/materials in daily. I've never went through a toll over class 2 (10,000).

9 years ago I could tell the rear felt weird coming down the highway(we got a few flats on this job) and quick pulled over, the tire was just starting to look low, but you could see the groove wearing into where the tread met the sidewall and it was hot and soft. I dodged a bullet that day.

 

[nissanh]

Not at all... I am ready to learn

I found this from the link "4 Ply Vs 10 Ply Tires Meaning: Is 4 Or 10 Ply Better? - https://www.stocktonwheel.com/4-ply-vs-10-ply-tires/"

"What Is A 10 Ply Tire?​

The term “10-ply tire” describes 10 layers of rubber-coated cloth cords that cross the tread and sidewall, giving the tire’s structure strong support and greater load capacity"


These rubber coded cloth cords should not rub one another. Low pressures make these cords to rub/relative movements to one another right where the tire touches the road weakening the sidewall and the rigidity.

Think for a moment, 10 layers should stay together to maintain the strength, but when these 10 layers are moving respect to each other at each revolution for 30K miles, how much wear can happen.

I spoke to some of the tire techs at Discount tire and tire rack and they informed me to keep the pressures above 40 PSI for a 10 ply tires.

 

[Bisho]

They are not saying 9k lbs. They are saying 2117 lbs x 4 = 8468 lbs.

Curb Weight is approximately 5400 lbs. GVWR = 6856 lbs. Payload= 1456 lbs

They are conservative because one could theoretically put almost all that 1456 lbs over one axle. The weight balance of the 100 is near 50/50 so 5400/2=2700 lbs. Add 1456 lbs and you get 4156 lbs. Two tires at 2117 x 2 = 4,234 lbs... so right about there.

I was referring to Toyota’s OEM number (from post 47), which comes out to 9304 lbs. you’d need to load gold bricks over the rear axle with no driver, and I think the front tires would come off the ground, but theoretically most anything is possible.

But even then. Toyo says their tires can support that weight with 30psi.

 

[hoser]

Yes, I'm reading the same. 2326 lbs for passenger vehicles but downrated to 2115 for SUV/LT/Van usage. Really, like you said, nobody would put 100% payload weight over the rear wheels but 90% can certainly be in a pickup truck/5th wheel situation. If the front is coming off the ground, then you have a lever and the weight is behind the rear axle.

 

[NE Snowman]

Also, the 2500 is set up with e-load tires from factory and my TPMS lights will come on at 59PSI or lower in the front and 69 PSI or lower in the rear.

I am not a tire pro or claim to be but have always had high PSI on my e-loads.