Measured my tire wear (20,000+ miles at elevated pressure - 44 PSI)
 

I bought my ZX2 over a year ago with these tires on it. I am not sure how many miles they have total, but I have been running my Michelin Rain Force MX4 tires for over a year now (20,000+ miles) at elevated pressures (38 initially now 44). The other day I was working on a noisy brake and decided to measure the tread depths of the tires to see how even the wear is. I measured each of the three grooves in the front and rear of the tire using a depth caliper and averaged the readings. Here is what I found:

LF:
Inner-.207
Middle-.220
Outer-.197

RF:
Inner-.217
Middle:.230
Outer-.215

LR:
Inner-.225
Middle-.235
Outer-.220

RR:
Inner-.205
Middle-.215
Outer-.195

Interesting how even at the elevated pressure, the middle still has the most tread remaining and the outers wear slightly more than the inners. Maybe if I raise the pressure a little more, the wear will even out to the middle?

Thought? Any one else measure theirs and post results.

FYI: New, these tires had .320 tread depth.
http://ecomodder.com/forum/member-mo...-tire-wear.jpg

I always thought they just expanded to the diameter of the steel belts, so that they don't bulge in the middle like a balloon with additional pressure.

So wearing on the edges is normal as they are the "front line" when cornering.

I measured a couple new sets when I got them and found they had deeper tread in the center when new. So in my own use I'm not aiming for even tread across the width. I do suspect that higher pressure won't cause (much) reduction in center tread depth.

Mine are rated 44 psi; I'm running them at 50. Still have deeper tread in the middle after about 25K miles put on the tires which I bought new.

that is really good,
i wore out my current set from 1-16-09 to now pose to get a new set this week in just 20000 miles. but i had some suspension problems. slack in inner tir rod, rotted out rack bushing, no allignment in 5 years, worn out shocks and coils.

all new now, new rack and pinion, new poly sway bar bushings, new bilstein 5100 shocks , new coils, new new poly rack bushings. all new for the front.


i would love to get 40k out of a set.

I ran my OEM tires for about 48,000 miles at between 40 - 44 psi and they wore perfectly even and I got more miles out of them then most people I have talked to at yourcobalt.com and cobaltuniverse.net

I believe the tire lifts the front and back of it's tread patch more then it's left and right sides.
There are still safety issues with a reduced contact patch and braking though.


I see a test coming up.
Jack up the front of a car, put some washable paint on the bottom of the tire then lower it onto a piece of paper.

Try that at 15 psi, 30 psi, 45 psi and measure the difference in contact patches.
Would be a solid way to see what changes.

I'm working 12 days strait without a day off and about 55 hours a week so no chance I'll have time to try this anytime soon but if somone else wants to give it a go they are more then welcome.

Have you since tried to increase the pressure further to get more even tyre wear ?

It worked for me ;)

I have increased my pressure from 32 to 45 psi in the hopes of getting better mpg and getting more even wear on my tires. It may help even the wear slightly, but I still expect the outsides to go first. My understanding is that modern radials don't change wear patterns as much as tires of the past.

Perfectly even tread wear and 5% loss of tread depth after 24,000 miles. That's at 44 PSI, the rated max pressure. Measured to the thousandth inch with a dial caliper.

Same for another set of new tires (both sets bought new) on a different car.

Running my Altima factory tires at the same pressure.

Tires last a lot longer (less heat buildup and stress on the sidewalls).
Lower cost per mile due to longer tire life.
Significant increase in fuel mileage.

After 60k miles of running higher pressures I will never go back, and I drove over 600k using manufacturers recommended pressures over the last 45 years. Worked in the auto repair industry from 18 until 50 and ran my own shop the last 15 years.

regards
Mech

How the car behaves?
 

Guys, what is the rated max pressure for your tires? And how about breaking/handling changes? I thought 44psi would be the pressure limit for a regular radial tire to be inflated.
Well, also here it would not be too good, the roads/streets floor around here is terrible. The car would behave like a pioneer´s cart...

I'm on my third set of tires on my 06 Civic. The wear pattern has always been the same. There is extra wear on the inside versus the outside. Either something is wrong with my car or Honda set the camber so that the bottom of the wheels are angled outward. Don't remember if it's that's positive or negative camber. I'm guessing this increases stability like standing with your legs separated.