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Author Topic: Measured my tire tread depth.......  (Read 6208 times)

SargeW

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Measured my tire tread depth.......
« on: January 09, 2009, 09:23:05 PM »
I have had my 32' Itasca Meridian for almost 3 years now and have just over 23,000 miles on the clock.  I have never rotated the tires, but I pay close attention to the tread wear and pressures.  A few days ago I got the idea to check the depth of the tire tread on each of the tires and compare it for wear.  I have a simple tread gauge that has a probe on one end that goes into the tire tread, and the other is a marked gauge that pushes out depending on the tread depth. It is marked in 32nd's and millimeters. I used the 32nd side for my readings.  I figured that if I checked a tire all the way across the tread face from outside to inside, if there was a significant difference in the depths of each tread it could indicate if the tire was running too high or too low of a pressure. 

I was surprised (and pleased) to find that for the most part the tread depths were pretty even across all the tires.  I was surprised to find that my front tires averaged between 12/32 and 13/32 in depth of remaining tread.  The rears which I reasoned would have a little more tread since they are duals and only push the rig.  Instead I found that the rears averaged between 11/32 and 12/32 of tread depth.  Not a huge difference, but I always assumed that the front tires were taking a lot more punishment steering and taking 75% of the braking load. There was a slight decrease in depth in the inside of the rear inner duals, about 1/32, which I assume is due to the scrubbing of the inside tire when the rig turns a corner.  Both side of the rears measured similarly, as did the fronts. 

I'm not exactly sure how much tread that they had new, or how long they should last, but they still look to be in great shape and the ride is smooth.  They are Michelin 255/80/22.5 XRV and are OE. I had a four corner weight done when I started to full time, and currently am running 95# in the fronts, and 85# in the rears, and that still leaves me with a good safety margin according to Michelin's weight charts.  When I had the four corner weight done and compared it to Michelins weight chart, it indicated that I could actually run the fronts at 85# and still be within specs.  However, I tried it for a 350 mile trip and the front end felt kind of "squishy" and wandered  in the road grooves a little too much.  I increased the the fronts to 95# and it corrected itself right away.  I also have been using a Tire Pressure Monitoring System for about 2 years now, and wouldn't be without it.  Great peace of mind.  Just a little food for thought. ;)

Sarge
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afchap

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Re: Measured my tire tread depth.......
« Reply #1 on: January 09, 2009, 10:15:08 PM »
I just replaced the last four original tires on my '03 coach. They looked great and had lots of tread left at apx 48,000 miles, but would be 7 years old next month. I'm sure yours will have plenty of tread when they are too old to safely run. Most RV techs say just forget about rotating your RV tires for that reason. They say it isn't worth the time/trouble/expense.
Paul ... (KE5LXU), was fulltimin', now parttimin'...
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'05 Honda Odyssey toad
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Ned

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Re: Measured my tire tread depth.......
« Reply #2 on: January 10, 2009, 07:16:20 AM »
It's unlikely you'll need to replace a tire due to tread wear before they age out at 6-7 years.  These are basically truck tires and RVs just don't put on the miles that they get in commercial service.
-- Ned -- Fulltimer 1997-2013
1997 Holiday Rambler Endeavor LE
2007 GMC Canyon

John Canfield

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Re: Measured my tire tread depth.......
« Reply #3 on: January 10, 2009, 07:32:58 AM »
I'm with Paul and Ned - we haven't rotated and most likely won't.  I'll replace them at seven years.  Just noticed a little ozone/UV/whatever cracking in the sidewall, but it is minor at this point.
--John
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SargeW

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Re: Measured my tire tread depth.......
« Reply #4 on: January 10, 2009, 08:20:39 AM »
A buddy of mine in So. Cal. has a set of Michelins on his Classic MH.  His were approaching the 7 year mark but also looked like new.  He called Michelin and asked them about their longevity.  Michelin told him that as long as the tires are in good condition on the outside, are used regularly, and inspected once a year that they are revising their life span estimate to 10 years.  He was delighted to say the least. I am putting some pretty good mileage on the tires since I started full timing, so I will test their longevity.  We are in Florida right now, and are heading back West in February to head into Alaska in the spring.  So I will be putting on a few miles........   
Marty--
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Ned

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Re: Measured my tire tread depth.......
« Reply #5 on: January 10, 2009, 08:40:48 AM »
Unfortunately, the tires may look fine on the outside at 7 years but may be rotting on the inside.  Did their definition of inspection include dismounting the tire for a full look, inside and out?  The cost of a blowout could easily exceed the cost of new tires.  I'll stick with a 6-7 year replacement policy, even if I had Michelins, which I don't.
-- Ned -- Fulltimer 1997-2013
1997 Holiday Rambler Endeavor LE
2007 GMC Canyon

geodrake

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Re: Measured my tire tread depth.......
« Reply #6 on: January 10, 2009, 09:09:38 AM »
I put Honkook tires on our first MH. They were quite reasonably priced and we put about 12K carefree miles on them prior to selling and buying the current rig.  Has anyone else had experience with these?
George Drake

Gary RV_Wizard

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Re: Measured my tire tread depth.......
« Reply #7 on: January 10, 2009, 09:40:57 AM »
Quote
in good condition on the outside, are used regularly, and inspected once a year that they are revising their life span estimate to 10 years

It's the "inspected once a year" that is the rub. You can't tell diddly squat about a tire's condition looking at the outside, unless there is a deep gash in it. You have to dismount the tire and look at the inside of the walls to detect signs of failure, and even then it takes a real expert. A look at the outside by the guy who changes tires for a living doesn't cut it.

I recently had an excellent looking tire fail at just over five years. Fortunately I saw the big bulge in the sidewall while it was parked and did not have to find it the hard way.

Your friends tire may indeed last 10 years, but the odds are against it and they increase with age.
Gary
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Ron

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Re: Measured my tire tread depth.......
« Reply #8 on: January 10, 2009, 10:13:18 AM »
When we replaced the tires on our Eagle they had over 90k miles on them and looked very good with no signs of cracking with excellent tread.  We replaced them because they were over 6.5 years old per the DOT date stamp on them.  Anybody running tires more than 7 years old since manufacture is just taking a big chance.  I wonder if the 10 year information mentioned was actually from Michelin or a dealer since it could lead to serious damage due to tire failure.
Ron & Sam-home is where we park it. Currently located   HERE

John Canfield

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Re: Measured my tire tread depth.......
« Reply #9 on: January 10, 2009, 12:16:53 PM »
10 years - that's pretty old for any tire IMHO.  I would not be comfortable going past seven years - it's a peace of mind thing.
--John
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SargeW

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Re: Measured my tire tread depth.......
« Reply #10 on: January 16, 2009, 03:13:26 PM »
All very good points I must agree.  The info was from the Michelin customer service line.  And I agree, it's a matter of preference when to change tires.  But even as RV Roamer pointed out, his tire failed at 5 years, well short of the 7 year mark.  Just passing along information from a manufacturer.  Usually using the tire is the best way to treat it.  Pulling into a RV spot and sitting for several months on end is the worst thing.  I also agree that dismounting the tire for an inspection is also the best way to inspect it, but that is also not a guarantee of longevity.  If there is a doubt in anyones mind, always err on the side of caution.

Sarge
Marty--
2017 Tiffin Allegro Bus 40SP
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