Increased tire pressure and center wear (tread depth checked after 1 year / 30k mi.)

[mcrews]

90% of all tires on vehicles today are steel belt. period.

the center wont 'expand'.

[oldtamiyaphile]

Originally Posted by Frank Lee

I stopped by a tire shop to borrow their tread depth gauge a while back to see how my inflation strategy was working. F150, tires only a few years old, I'd guess less than 20,000 miles. From new I tried 50 psi (44 sidewall max) but it rode like it had solid tires so I backed off to 46, which they've been at practically the whole time. The center is wearing faster than either of the sides, front and rear, on both sides. So I'm going to back off at least 4 psi and see how that goes.

The Goodyear Wranglers on my Jeep have worn away twice as fast in the centre as on the edges at max side wall over about 20K miles. The Kumho's of the same size on a similar weight/ size Isuzu didn't have as much of a problem.

I've been told that over pressuring has positive affects on tyre life, even if the centres wear first, you still got more life than aiming for even wear. In the case of my Goodyears, they're on track for ~40k miles, which is better than the more even wearing Kumho's got.

At any rate, tyres are generally cheap compared to fuel.

[Frank Lee]

Originally Posted by mcrews

90% of all tires on vehicles today are steel belt. period.

the center wont 'expand'.

That's great. Tell that to my tires and the depth gauge.

That STEEL belt is composed of WIRES.

YMMV.

[niky]

Yeah, YMMV. On regular round-shouldered tires, I've never seen excessive center wear... but on my Neovas before, the centers wore out faster than the edges during tire rotation intervals where I'd done no track time.

Still worth overinflating a bit, though.

[CapriRacer]

Just so everyone understands:

The steel belt in a steel belted radial tire (way, way, way the most common kind!) RESTRICTS the growth at the center of the tread but does NOT eliminate it.

The wear on a tire is affected by the inflation pressure - BUT - there are other factors that are more significant. So you will get varying answers on uneven tire wear relative to inflation pressure as it is more dependent on other things.

For 8 years now, I've been cataloging reports on what affect ..... ah ......... let's just call it "elevated" inflation pressures have on things - and here is what I have amassed in 15 pages worth of anecdotes:

There is a tendency towards center wear. There is some loss of traction, especially wet traction. Tramlining (groove wander) seems to be an issue. Harsh ride is frequently reported. The data seems to point to more tire failures, but of all the information cataloged, this is has the least number of data points as not only are "normal" tire failures rarely reported, but the difference appears only to be perhaps a factor of 2.

That's the bad news!

But the good news is that fuel economy is improved. Tire wear rate is improved. Handling is quicker and more precise.

It is unfortunate that many things affected by "elevated" inflation pressures in tires haven't been studied more rigorously - but they haven't! What we have are anecdotes - and as with all anecdotes, there is plenty of room for .... uh ...... "discussion". I have no doubt that we are in for further "discussion" on this topic.

[secaturbo]

Hey CapriRacer, Do you road race in IT?
I used to race a CRX si in SCCA showroom stock class late 80s. Used the Yokohama 008 tire. At a national event a Yokohoma rep said to me on the sly inflate to 45psi cold and run in lap or two come in and tire should be 50-52psi hot.
Side wall i think was 38psi. I did this and handling was much better.
Guy at Jackson Racing confirmed this and he said as high as 55ps hot.

They say this pressure keeps sidewall from deforming at hi cornering speeds. BIR turn 1 was about +110mph.

I run my G1 Insight at 60psi no issues. But just bough new in Oct so I will see how they do and report back.

[CapriRacer]

Originally Posted by secaturbo

Hey CapriRacer, Do you road race in IT? .......

Back in the early 1990's I did. I had a 1974 Capri with a 2.8L running in ITA. I totaled that car - 2 1/2 rolls that damaged every panel on the car. I replaced that car with the GT3 Capri you see pictured.

Originally Posted by secaturbo

........ I used to race a CRX si in SCCA showroom stock class late 80s. Used the Yokohama 008 tire. At a national event a Yokohoma rep said to me on the sly inflate to 45psi cold and run in lap or two come in and tire should be 50-52psi hot.
Side wall i think was 38psi. I did this and handling was much better.
Guy at Jackson Racing confirmed this and he said as high as 55ps hot.

They say this pressure keeps sidewall from deforming at hi cornering speeds. BIR turn 1 was about +110mph.

I run my G1 Insight at 60psi no issues. But just bough new in Oct so I will see how they do and report back.

First, racing is a totally different thing than running on the street. In racing, the tires have to last 10's of miles, not tens of thousands of miles. The difference is where one is on the SN curve. So using very high inflation pressures when racing on street tires is not the same as using that pressure in a racing tire or in a street tire on the street.

And, Yes, I used over 40 psi when I raced in ITA. I did that because I could not get enough camber into the car to keep the tire planted. I also noted that the crisp steering was an asset that help a poor amateur driver do a better job.

[secaturbo]

I new it. Loved those Capris
Agree racing different than street cause the Yoko-008s were very soft and sticky, I remember coming into pits during practice, checking pressure and going back out forgetting to strap in. Turned in for first corner and slammed against the door and steering wheel. Average person has no idea the cornering force a stock car can generate with the right tire.
Still think tire pressure can be at sidewall for best mpg,rain,snow only thing is drag racing, less is be better.
Just look at your web page nice.

[redpoint5]

My experience with increased tire pressure agrees with Capri's comments above.

I suspect increased tire pressure would also increase tire punctures since the area of the contact patch is reduced, increasing the weight placed on the part of the tire in contact with the ground.

[mcrews]

Originally Posted by Frank Lee

That STEEL belt is composed of WIRES.

YMMV.

ok.........thousands of wires woven & bound together to form a steel belt......your point?

Look, I watched a 8" round cold steel bar be stretched down to a 6" round cold drawn steel bar at a steel mill. But it took a locomotion train to do it.

Blue jeans are made of fine thread, but they don't fall apart because they are woven.

your point is weak.