Hyperinflating tires

[tasdrouille]

Originally Posted by MazdaMatt

[..]A "hyperinflated" tire will wear in the centre faster than a "proper inflated tire" will.

Can you prove it? Plenty of hypermilers that actually have ran their tires "hyperinflated" are saying otherwise.

[PaleMelanesian]

Originally Posted by MazdaMatt

3 different tires on 3 different cars at 3 different life spans really doesn't prove anything.

But it pokes several holes in a statement that hyperinflation WILL wear out the centers. At best, you can say it MAY or MIGHT.

[MazdaMatt]

Can i prove it - I suppose not. I'm just highly skeptical because of the "proof" that was given to me to refute what I would "assume" (a poor study and a set of random pictures of tires on different cars in uncontrolled conditions). My knowledge of tires is mostly on the race track. A tire that heats up in the center more than the shoulders will wear more on the center than the shoulders. This center heating is solved by lowering the pressure. Similarly, a tire wearing too much on the shoulders is corrected by adding more pressure. These are not some super special racing tires, they are DOT approved radials with a "R compound", otherwise the same as a street tire, just engineered to stick better at racing temperatures.

[PaleMelanesian]

Originally Posted by MazdaMatt

a tire wearing too much on the shoulders is corrected by adding more pressure.

exactly.

A tire that heats up in the center more than the shoulders will wear more on the center than the shoulders.

If you find this happening, then absolutely, lower the pressure. I'm not seeing center wear, though.

[MazdaMatt]

Originally Posted by PaleMelanesian

exactly.

Uhm... nice of you to filter out a tiny portion of my post, but... please, read the rest. A tire wearing too quickly on the center line is corrected by reducing the pressure. I don't need to inflate to 60+ psi to get too much center wear! that happens at a couple psi above "optimal" where "optimal" is most even tread wear and depends on the track, the weater, etc, but is typically around 30psi on my more racey tires and around 42psi on the tires i described above.

[PaleMelanesian]

Do you have any data on street driving? Track conditions are very different.

[MazdaMatt]

I'm just trying to alleviate broad sweeping comments that higher tire pressure will absolutely generate more even wear and longer life. If that was true, i'd put 2000psi in my tires and get incredible mileage and tires that last forever. The same study that "proved" that higher makes for more even wear and longer life also tried to "prove" that it generated more braking ability and cornering ability... this is wher ethe study forgot to find out that there are limits and made the sweeping generalization that higher=better for all parameters all the time.

And as I said, no, my assumptions (I'm not all-knowing and not claiming to be) are from stressing out a tire on a race track.

[PaleMelanesian]

Thank you for sharing some information that most of us have no access to. 42 psi on "normal" tires? That's a good data point. It's also well above the vehicle's recommended pressure and pretty close to sidewall max.

[MazdaMatt]

Sidewall max on these tires is 52, i believe. Toyo Proxes RA-1 (they make other proxes, be sure to check RA1 specifically). So it is half way between "vehicle recommended for driving on the streets" and "maximum rated safe pressure for the designed load of the tire". It is not an extreme point.

Now, here's something that may validate your points a little. I am using 42 PSI to combat sidewall wear because I turn as hard as I can on the race track. Hypermilers typically also turn very hard on the streets to maintain momentum. This could be the cause of the rather even tire wear experienced by some. The same overinflation by someone that does not corner hard would result in a more center-biased wear pattern.

Using the more racey tires that have "optimal" tread wear around 30, i also have a LOT of negative camber (2.8*) which allows me to corner hard and keep the pressures down.

[PaleMelanesian]

You may be on to something there with the cornering. I do corner harder than I used to when I was a normal driver.