Let's talk tires

[BHarvey]

Tires are an interesting subject, with hundreds of styles of tread, width, height and weight. After playing with tire pressures I have noticed that since the majority of the weight in a car is over the front tires, the fronts need 44 psi to look like 34 psi in the rear. That's easy.

But if you look at the wear marks, if you have any visible part of the tread block (side of tread) touching the pavement it could be viewed as slightly under inflated. The tread should be flat with the pavement correct?

It is also a known that heat destroys tires. Well, just say for instance a correct inflation pressure is 40 psi... Now if you have 30 psi the tire will generate more heat than if at 40 psi correct?

That heat burns the oils out of the rubber.

It is interesting that the tire companies, as well as most "authorities" say 32-34 psi is 'correctly' inflated. I have NEVER seen a tire that looks 'correctly' inflated with that low of pressure IN THE FRONT TIRES!
The rears look good on most cars with that pressure. The only exception is of course low profile tires as they can look good and have a flat contact patch with 20-40 psi. (This is why the car magazine guys never see the big benefit we see) Seems like aspect ratios of 65 and over are the ones that show a big benefit from increased tire pressure.

My 85 Corolla showed a 7 mpg gain from 34-44 psi. (85 aspect ratio)

Now take into account if you run 32 psi all around and rotate your tires every 10k that all the tires are spending equal time being over loaded and under inflated on the front of the car.

We also know that a truck that hauls heavy loads will need more tire pressure to not overload the carcass.

So it seems like 'correctly inflated' is the inflation pressure that is required to keep the contact patch flat with whatever loading is present with a given aspect ratio.

It's funny that the majority here have found that with more pressure (over inflated according to the authorities) that they see longer life, better wear as in wearing flat, increased mileage (of course).

Now here's a major question that all should try to answer.
We know the tire companies say a tire last 6 years.

With running your increased pressures, that keeps lower heat in the tire, have you worn the tire out before 'dry rot' starts?

[Frank Lee]

I inflate the fronts more than the rears on my fwds.

I have had many tires fail (blow out) that still had lots of nice deep tread. Failure mode is sidewall blowout due to intense weatherchecking.