The PSI could spike up to that if someone were to go over a pothole fast with pressure above max sidewall.

As for me, I simply set my tire pressure to what I feel gives me the best mix of handling/ride. I find that going from 30 to 44 (dunlops with 51 max) seems to be my favorite, as it handels a bit better, and the ride is still not too bad. I also find that I can coast longer when rolling to stop signs from a given speed with the tires at higher inflation. True that's just my anecdotal evidence, not scientific testing, but that would still imply improved mileage with higher pressure.

You forget that higher PSI means more load carrying capacity so while the psi will go up it won't go up as drasticaly in an tire with a higher psi than one with a lower psi. The pressure in the tire will make it much less prone to flexing unlike a tire with lower pressure. So because of these two facts (lower psi tire will flex more allowing air to push against the tire walls that aren't in contact with the pothole edge, and the fact that the lower PSI tire has less load capacity (can sustain less force on it than a higher psi tire)) we can conclude that higher PSI is always better than lower PSI and is not any more dangerous and likely safer.

If I have a tire at 50 PSI won't I have to compress it by half its volume to get it to increase an equal 50psi? If I do that I will probably have to crack the rim of my tire.

As for you getting milage at least thats something I can agree with you on I hate being so contrary in my posts but I'm sick of people coming in here and saying higher psi is going to kill you or is likely to blow out your tire when infact lower psi is more likely to cause this.

My hydroponics experiment

You ever notice how hard it is to lip read cartoon characters?
"Crazy is what the sane call Delta Flyer"

It's okay with me if you don't "buy my story."

Let me tell you two of the most common ways to "assume" that the tire was over-inflated [after it exploded]: 1) The other three tires on the vehicle are over-inflated, and 2) the customer tells you that they over-inflate the tires themselves.

Over-inflated/under-inflated - both not recommended. What's wrong with keeping the tires at the recommended limit of 44/51 (depending on the make)??

If you want to fill your tires to 75psi or whatever, go right on ahead and do it, I just don't recommend it.

Tempus fugit, memento mori...

Hey Lee this is interesting.

When you see exploded tires and you measure overinflation on the others,
how much overinflation are you talking about?

Do you actually see people inflating their tires well over sidewall max?

What you have described only attempts to prove by assumption, that the tire that exploded was over-inflated. It in no way proves that the over-inflation caused the tire to explode.

Like Tom, I too have been told by a tire engineer that the minimum design criteria for a tire is over 100 psi. This makes sense to me because an engineering rule of thumb is to design, under fairly well defined conditions, to a factor of safety of 2 or 3. That would put the design pressure of a 35 psi rated tire to 70-105 psi. But for products where personal safety is a concern, such as tires, the factor of safety would be increased significantly. Possibly as high as 4 or 5.

It's a Wonderful Day for Science!

Perhaps we should turn the exploding tire question over to Myth Busters the TV Show?

'07 HCH w/Nav, '04 Corvette Z16, '98 Corvette Pace Car, '04 Chevy Avalanche.
HCHII Mods: Tinted windows, PIAA 4150K Headlights, PIAA 004X Fog Lights,T/P F/R 48/46 nitrogen.

good idea!

My hydroponics experiment

You ever notice how hard it is to lip read cartoon characters?
"Crazy is what the sane call Delta Flyer"

Of course it's by assumption, that's why I put it into " ."

None the less, having worked at a Tire store for almost three years - albiet not making me any kind of expert on the topic at hand - it is a general "no-no" to over-inflate the tires.

Tempus fugit, memento mori...

Tires are certainly over-engineered for safety as previously stated, but rest assured they'll go through a lot of analysis of the tire's ability to handle stress. They'd have to consider the wide range of speed involved, potential weight load on the wheels, and severity of impact (say with a pothole). Unless they want a 30 lb tire with 1.5" thick rubber sidewalls, they'll have to draw the line somewhere and engineer something that is safe under 99.9% of the conditions you'd encounter. The more you overinflate a tire, the lower that 99.9% bar becomes. At 50 psi, you may be putting yourself at risk for the kinds of impacts that would be safe at say 32 psi. Granted that range of risk may be way off the scale, like hitting a pothole at 90 MPH, but you still introduce risk of the tire withstanding a pressure spike (I'd bet a damaged sidewall would also have a lot to do with the risk of a blowout). So while overinflation may not cause a blowout by itself, it most certainly would increase the risk of one.

*** Retired after 65,000 outstanding miles ***

Hi;

I have myself thought about this same thing, concerning why Honda recommends one tire pressure over another?

I think all manufactures, take into account the (Majority) of owners wishes concerning their ride and also the FE.

So, with that being said Honda I'm sure knows that by increasing the Tire Pressure would increase the MPG, but in return take-away from the comfortabe ride. They compromise, which is a smart move on their part. Most owners would rather have a nicer ride and give up thr 2-MPG trade-off for the better ride. (IMO)

My 2-Cents.

Terry

tigerhonaker
2007 HAH
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