Tread depth after 15k miles
 

Had the 175-70-13 tires on my VX rotated and balanced after 15k miles Wednesday.

Two front tires (now on the back) average tread depth .215. Maximum variation no more than .010.

Two rears (now on front) average tread depth .250. Maximum variation no more than .010.

These tires were inflated to 44 PSI since they were installed new (sidewall max).

No consistent variation between the outer and center grooves (3 grooves per tire).

At least for these Michelin X tires inflation to sidewall max has no effect on increasing or decreasing the amount of wear from the center groove compared to the outer grooves.

Checked with a dial caliper.

regards
Mech

I would be worried about damaging the tire...

Heat causes expansion. When you're driving down the road the tire pressure will normally rise 3-4psi.

Or do tire ratings take in that heat expansion when they stamp them for a max?

(I just don't want you to damage your tires or be a hazard!!!)

Above efficiency comes safety!

Max tire pressure is cold so yeah, they should take an increase in pressure when driving into account. That's also why they state you should inflate them cold.

the bolt pattern for honda, you could step up the tire ratings easy. the little 13s can't even do highway..there are trailer tires with greater ratings.

I learned this with 13 years of old subaru, the last 3 years have been with 15 inch wheels versus 13.

I have no sign of wear, 16-20k miles, and saved fuel.

the FWD and lightweight of the honda should not be a deterrent for greater wheel tire combo. At 15 inch you can go all ratings, I choose "T" and 89 weight. 13 inch canlt do much, and even 14 inch has limits.

The little wheels save nothing and are even life risking.

Please explain.

1036 pounds max load per tire on a 2100 pound car with a 850 load capacity leaves a margin of over 1100 pounds (easily twice the load capacity and over 400 pounds more than the original tires).

My point was after 15k miles on these tires there was no difference in tread depth with 44 PSI pressure. I check the pressure monthly.

The ride is more harsh with higher pressures, but I see no change in handling, might even be a little better. I do tend to take corners fairly quickly since I avoid brakes like the plague. Not crazy fast like when I was young but sometimes fast enough for the wife to be grabbing something to hold on to ;).

Last 5 tanks of gas averaged 52 MPG in rotten weather here. That included one tank at 46 MPG with average speeds close to 70 MPH.

These are supposed to be 80k mile tires. Tread wear difference between front and rear is about .035 after 15k miles. Tires replaced the ORIGINAL Bridgestones that were made in 3-93 (that's right not a misprint) 10k miles after car was rebuilt at 27,492 miles (original) right at 2 years ago in March.

From comparing the difference in tread wear (.035) to the tread left .215 and .250 it looks like they should easily make it to 80k, maybe even 100k.

I paid less than $46 per tire at Costco with an additional $10 for lifetime rotate, balance, and hazard warranty. When first replaced my mileage dropped significantly, but it seems to be coming back up now. Used to average close to 60, in the summer, probably get about 57 or so this summer. Ride and noise are so much better the trade off is worth it.
My hypermiling is not as intense as it was when gas was at $4 a gallon here in the summer of 08. One tank then was 68 MPG all freeway at 64 MPH 150 feet behind a big rig staying in the right lane (on a 3 lane interstate) for 300 miles.

Odometer is off 1% due to larger diameter. It was off -1% with the worn out original tires, actually not worn out but sidewalls cracking bad enough to not want to risk driving them any more.

regards
Mech

good news!

My summertime inflation pressure is 44psi also. The sidewall max is 35psi. I have checked after driving, and even on a hot summer day, the pressure was no higher (I use a dial type gauge, not cheapo). The higher initial pressure reduces the flex in the sidewall, and thus reduces the increase in tire temperature. 'Stiffer' tires run cooler. Here's my old thread about when I measured my tire wear recently.

http://ecomodder.com/forum/showthrea...ear-10265.html

I try to keep my Cobalt's XFE tires at 44 ppsi Tops. Recently I noticed 2 of my tires have dropped 5 pounds in a year, still far above G.M.s recommendations, but I already have a good feel for how long these tires should last based on this first 10,000 miles at high inflation rates, well over 30,000 miles, hopefully a lot more. I rotated them a year ago, will do so in September. I barely notice any tire wear at all. Stock Chevy Cobalt XFE High Resistance tires. I believe in keeping an eye on the tire pressure and rotating my tires every 10,000 if they need it or not.