Hyperinflating tires

[dichotomous]

seems the best way to ride at high pressures is to find a light truck tire that will fit your car, and run that at very high pressures that it can take.

[cfg83]

CapriRacer -

I would like to thank you publicly for your classy responses. In an ideal forum, we'd have an expert like you in each "mod-category". This way, people would be in a position to make "informed choices" with the best information possible.

CarloSW2

[trikkonceptz]

I am one of "Those Guys" that runs pressure well above the placard limits.

Placard says 32psi, I run 55 on all 4 corners. I am on my second set of tires with those conditions.

1 set had 46000 miles on them and 60% tread life left when I switched them for my current new tires.

The tire guy could not believe the mileage and condition of the tires until he looked it up himself since I bought them there originally. That alone changed his opinions on tire pressure.

The car handles better in the Florida Rain, definately in the dry, obviously has helped me get to my FE #'s and yes the car does ride rougher, the only draw back.

Florida sees some pretty evil potholes at times plus tons of construction zones on the hwy. I honestly believe that the condition that would puncture a tire @ x psi will also puncture the tire @ 55psi.

In the end remember the industry that designs the tire also sets the reccomendations for how they are to be used. It would not be in their best financial interest to put a product on the road that will last three times as long as the current trends. Most of us put a new set of tires on a vehicle within our estimated usage.

Imagine if that was not so, it would put a hurt on the tire industry. There is more money to be made with replacement parts than the vehicle itself. No industry will ever develop the part / car that lasts forever, its just not good business. That alone has to weighed into any argument for or against this topic.

[rmay635703]

I agree with trikkonceptz except for one point. (Note* I have never run vehicles at the stock pressure, always above, )

Two things I have noticed
some tires seem to last forever but then end up with uneven wear far past their prime
other tires run above their rating get sidewall rot earlier than they should

So its a mixed bag whether or not you will actually get better tire life from overinflation. On my Suburbans its tends to be the opposite, on lighter vehicles it seems to extend life.

Not sure if there is much that can be done for sidewall cracking but that is the only real failure I have ever gotten on tires in that the side wall blows or developes a slow leak.

[trikkonceptz]

Originally Posted by rmay635703

Not sure if there is much that can be done for sidewall cracking but that is the only real failure I have ever gotten on tires in that the side wall blows or developes a slow leak.

This is not sarcasm, but what about maintenance? By that I mean washing your tires or scrubbing then when you wash your car. Or using a silicone based product to keep the sidewalls from cracking. I assume its refered to as dry rot, which would indicate that the sidewalls have dried up, kinda like when leather seats crack.

There is preventive maintenance to keep that from happening, those of you living in cold climates may have to stay on top of your tires a bit more than warmer climate owners.

[rmay635703]

Originally Posted by trikkonceptz

This is not sarcasm, but what about maintenance? By that I mean washing your tires or scrubbing then when you wash your car. Or using a silicone based product to keep the sidewalls from cracking. I assume its refered to as dry rot, which would indicate that the sidewalls have dried up, kinda like when leather seats crack.

There is preventive maintenance to keep that from happening, those of you living in cold climates may have to stay on top of your tires a bit more than warmer climate owners.

I'm not sure how well maintenance works, I made point for a while to be consistantly cleaning and treating the tires on my diesel suburban but ended up with the same issue not long after. To me it seems to be more to do with the type of tire more than maintenance as I've had several sets of very cheap "desert dog" tires that lasted close to 100k aka 8yrs of driving on that paticular vehicle and the sidewalls did not crack, eventually the tread fell off but the tires were only rated at 30000 miles. I've had more expensive tires start cracking within a few years, it is never consistant but I have to say it seems to happen much quicker lately like the tires aren't made as well. But yes I do live in the northern areas.

What types of treatment actually work? I have used several different types without much luck.

[CapriRacer]

rmay635703,

Some insight into sidewall cracking and why you may see some variation between tires:

The purpose of the sidewall rubber is to protect the casing from abrasion by curbs. This is more or less a "thickness" kind of thing. Sidewall compound doesn't have much effect. As a result, the sidewall compund tends to be the dumping ground for otherwise unuseable rubber within the tire factory.

There are different types of rubber and there are pretty extreme differences in ability to resist cracking. Unfortunately, some of these rubbers are unsuitable for use within the casing itself, not to mention use in the tread. That means that some tire manufacturers will use crack resistant rubbers in the sidewall and others won't.

Antioxidants (AO's) are used within the tire to slow the deterioration of rubber due to oxygen. AO's are very expensive and their use is carefully monitored within the tire factory. Use of AO's slows down the onset of cracking.

The net effect is: While cracking is commonly used as a tool to judge the state of the tire casing's rubber, it is somewhat unreliable. Clearly tires that have severe sidewall cracking likely means the casing rubber is also deteriorated, the reverse in not necessarily true. In other words, tires with little or no sidewall cracking aren't necessarily OK. Cracks in the tread rubber are a little better guage, but that is also a little unreliable, especially between tire manufacturers.

There have been group discussions between tire manufacturers about tire aging. Some tire manufacturers want their tires to look old when they ARE old, so the tire will be removed before the casing rubber reaches a critical point. In this case, "Old" means the tire's casing is deteriorated, which would be a combination of stress, time, and heat.


However, this is not a universally held position, so some manufacturers are inclined to view sidewall cracking as an item requiring a "fix" of some sort (as opposed to those manufacturers who view this as a tool to judge the state of the casing.)

[trikkonceptz]

Great reply Capri, but that opens up a couple more questions.

What enviromental factors contribute to aging a tire prematurely? Heat, Load, use? I am sure some of these factors can be traced back to improper inflation, meaning low tire pressure, which induces riding on the sidewall for example. Or can we throw in temperature extremes like driving in Florida during the summer, or a winter in Green bay.

Does lack of use contribute to said failures ...

So many questions so little people willing to answer .. LOL

[CapriRacer]

Originally Posted by trikkonceptz

Great reply Capri, but that opens up a couple more questions.

What enviromental factors contribute to aging a tire prematurely? Heat, Load, use?

.........

All of them.

Heat is by far the biggest contributor to tire aging. Some refer to the Arrhenius equation (wikipedia that!) which says that for every 10 degree Celsius increase in temperature, the reaction rate doubles. This means that hot climates will age a tire faster.

Then there is stress / strain. Stress would be analogous to the load on the tire and strain would be the load vs inflation pressure (or deflection) of the tire. Needless to say, the deflection also adds heat generation on top of the ambient temperature.

Speed is also a factor as increasing speed increases the rate of heat generation.

After that we get into all kinds of things that contribute to heat generation and stress and strain - hard cornering among them, but if we confine ourselves to reasonably normal car usage we can neglect these.

Originally Posted by trikkonceptz

..........

I am sure some of these factors can be traced back to improper inflation, meaning low tire pressure, which induces riding on the sidewall for example. Or can we throw in temperature extremes like driving in Florida during the summer, or a winter in Green bay.

.........

Funny you should mention Green Bay. I had a discussion today with a chemist on cracking in white sidewall tires. This is almost strictly a cold weather phenomenon and it is due to the way white rubber compounds are formulated. This is not normally a problem when carbon black is used as a reinforcing material.

Originally Posted by trikkonceptz

...........

Does lack of use contribute to said failures ......

...........

Yes, in that AO's will tend to migrate to the surface as the surface AO's are used. This is promoted by flexing of the rubber compound. An analogy would be the Partial Pressure of Gases (another thing to wiki!) except that we are talking about a mixture of solids. The easiest way I've discovered to envision this is spaghetti in meat sauce, where the spaghetti is the long change rubber compounds and things like AO's are bits of sausage in the sauce.

If the AO's are used up on the surface, the surface will tend to crack and no flex considerably slows the AO's migration to the surface.

[nowackim]

Recently (2015) I have heard about using pure nitrogen in tires. I tried it from Costco and they definitely maintained pressure longer.

Is this worth pursuing?