tireman9

Here is a link to more detailed info on Elevation (Altitude) change. Brett offers good advice on the minimum suggested inflation pressure. If you want more detail you can check this link.

Brett I only have limited information as I was not directly involved. The best I could discover was it was definately a larger tire. The Adjuster used that as the excuse that since the mileage was no longer accurate and the warranty was based on miles, the change voided the warranty. The Owner said they tried to argue with the adjuster and said they would accept a couple % decrease in the warranty life but according to the owner the adjuster was adamant. The current repair estimate was large enough that the Ins co would not approve the repair until the adjuster viewed the RV so it obviously was not a small claim. It appears the policy cancelation definitely worked to the insurance company benefit. In the brief discussion with the owner the conclusion we came to was that the insurance co was just looking for an excuse to avoid paying for repairs. The owner did say they were told they would get got a partial refund of their payments. (payments minus previous claims). Looks to me the Ins co was looking for a loop hole. My advice is to get something in writing from your insurance co if you are considering changing tire size. Nothing saying they have to be logical on their exclusions. Sorry I can't provide more details.

New Information for Don and possibly others. This week while at the Gypsy Journal Rally in Celina, OH I spoke with an RV owner who had their Extended Warranty canceled. They were having warranty work done but the adjuster who inspected the problem took a picture of their tires and of the RV placard then informed the owner that their policy was canceled because they had changed tire size. I’m not saying this is reasonable or that it will happen to others but in my opinion if one company uses this as an excuse to not cover some repairs others might also. People might want to take a close look at their policy before making a tire size change.

Are you sure the wheels are OK? According to Michelin data http://www.michelinr...tion-tables.jsp their XZA2 295/80R22.5 LRH tires are rated 7830# @ 120psi single and 6940# @ 120psi dual for each tire and their XZA2 315/80R22.5 LRL is rated at 9090# # @ 130 psi single and 8270# @ 130 psi dual for each tire. You didn't mention the brand wheel but if you have Accuride I am surprised that you were given 9.00" "Heavy Load" rims from Newmar/Spartan as that is what would be required to carry the 9090# at 130 psi. If you have Alcoa I wonder if you can provide the wheel part number as according to Alcoa their 22.5x8.25 wheel is rated for 8,050# max. http://www.accuridew...om/hubpilot.pdf http://www.alcoa.com...3901&cat_id=918 Also Michelin specifies 13.8 vs 13.2 minimum dual spacing. I think the Accuride wheels deliver 14.1 spacing but the Alcoa seems to be 13.32 which is OK for the 295 but not for the 315. Note its been a while since I figured dual tire wheel offset so I could be off on this dimension. Given the general level of "lowest cost part" mentality in the RV industry I would be very surprised if even Newmar would spend the extra bucks to provide the heavier wheel as OE, when your coach didn't need the increased inflation or capacity to meet DOT placard requirements. Would really like to see part numbers and data so I can learn where I might be wrong.

I have a post that covers rotation and matching duals. Pictures of the result of the RV manufacturer not setting alignment of the RV when new in the post.

I have a different brand TPMS but also occasionally lost signals. I traced the problem to radio interferance! I had installed a small back-up camera that was wireless from the rear of MH to the control box up front. Never had problems if the camera system was powered down. Ended up removing the camera and have had zero lost signals from TPMS in last three months which included two week long trips.

Wayne You might find my Sept 1 post on my Blog of interest. Focus on "I had a blowout"

I understand the reports of valve extensions leaking. However is the bolt in metal valves in the wheels have new rubber O-rings and the braded steel extensions are carefully threaded onto the valves and the hose is firmly mounted to prevent movement I see no reason for them to leak if they don't leak when initially attached. I have 15,850 miles on mine and my TPMS - inside tire mount - check tire pressure about every 15 to 30 seconds while driving. A quick spray with soapy water will show a leak. By the way I will use your experience as a teaching opportunity (minus your name) in my next Tire Seminar at Madison FMCA Convention and hopefully others will be able to avoid tire failure and the expense of replacing two tires by installing a TPMS.

I have read your post on the subsequent "Zipper" failure. I note in this post you say the tires were inspected. Did the tire tech dismount the tires and inspect the interior or did he just look at the outside of the tires?

Dayton is part of the Bridgestone/Firestone family. I believe Dayton truck tires are made in same plant with many of the same materials as used in other brands from the company. You can check HERE to see which plant made the tire. A few things to consider when selecting a tire brand: Where can you get the tire serviced or have Warranty work done? Does the company offer or include any road-side assistance? How big is their dealer network? Will you be able to get service near-by or will you have to return to the store that sold you the tires originally?

A general comment on Truck vs RV tires from a Tire Development Engineer. If we stay with the same size and Load Range, some tires may have some extra anti-ozone chemicals built into the sidewall but I am not aware of any meaningful structural difference other than advertised differences such as tread depth and pattern, both of which can affect ride & handling as well as long term durability and fuel economy. If you read the materials listed on the sidewall you will see that most tires for Class-A have one body ply of steel. The tread area may have three or four steel belts but usually the difference here is also related to expected usage which also involved different tread depth and tread pattern. Given that most tires on RV "age out" rather than "wear out" I would probably shop around for the tire with the shallowest tread as that would in all likelihood also give best fuel economy as well as be of lower cost with the possibility of better ride too. When you are inflating a tire to 100psi there is not too big of a difference in ride between tires when you do controlled back to back tire evaluations which in the real world probably no one here has ever done unless they have worked as a tire development engineer for one of the big tire manufacturers or a big car manufacturer. This type of testing involves running at identical loads & speeds over a specific set of road conditions with no traffic to hinder the test. When you get to the fine points there is no radio playing and the AC is off and all windows are closed so noise is not masked either. While an experienced & trained evaluation engineer might be able to feel a minor difference, most times the difference is well below the sensory threshold of 98% of every day drivers. Switching from shallow tread 6 year old tires to new tires is apples to oranges comparison as tread depth alone will vastly overshadow any possible construction difference.

I agree with Brett and have more extensive info on Nitrogen in my Blog

Haven't heard of any RV going that route. SIGNIFICANT up-front costs associated with buying the new wheels. Weight savings is only of real concern to truckers who are weight limited by most state laws. Fuel economy is probably improved but you will need lots of miles to offset the up front costs. Do you drive 50 - 100k a year? If so it might work out otherwise I doubt it. Note I worked designing "Wide Base" singles many years ago and there are savings to be had at the OE level where the cost of the special wheels and special tires is partially of-set by savings in the cost of 4 standatd wheels and 4 standard tires. but if doing a changeover you don't get thatat savings.

John No reason to be confused. What size are you currently running? ( Note to anyone reading this post. It ALWAYS is a good idea to include the current size and type and load range of the tires you currently are running when you start a thread on tire replacement)

Well so far I have received one PM with actual corner loads. Since I am presenting a seminar "Tire Basics for RV Owner" at Madison, WI Convention, I would really like some data from FMCA members and not have to depend on the other club members to provide actual data. I am sure there must be a few here who have had their coach weighed by RVSEF at a convention sometime.

Gary, FYI To my knowledge with the exception of a few passenger size tires going to OE with volumes exceeding aprox 10,000 a month, all tires are batch made, no matter the company. I have heard of similar supply issues with some Bridgestone, Goodyear and some Firestone items so this situation is not unique to Michelin.

John if you look at the Michelin listing you can then look at all the Micheline tires. If you click on the left ALL TIRES you will see the full list X XZ XZU XZY3 XCA XPS XRV XS XTE2 (wb) XZA XZA-1+ XZA1 XZA2 ENERGY XZA3 XZA3 ANTISPLASH XZA4 XZE XZE 2 XZE* XZE2+ XZL XZL (wb) XZU XZU wb XZU2 XZU3 XZY XZY3 XZY3 (wb) XD XDA XDA ENERGY XDN2 XRV XD2 XD4 XDA ENERGY XDA2+ ENERGY XDA3 XDA5 XDE M/S XDE M/S* XDE2+ XDL XDN2 XDN2 GRIP XDS XDS2 XDS2 (11R) XDY-2 XDY-EX XDY3 XPS TRAC X One XTA X One XTE X One XTE* XT-1 XTA XTA ENERGY XTA2 ENERGY XTA2 ENERGY (wb) XTE XTE2 XTY2 NOTE I have nothing to do with Michelin design nomenclature so don't blame me it they are a bit confusing. Looking at the XZE2 we see MI claims Enhanced application-specific compound to help promote resistance to aggressions and longer tread life. 6% wider tread for improved wear and handling (when compared to Michelin® XZE® tire). Matrix™ and micros sipes protect against irregular wear.™ Zig-zag grooves and sipes help increase traction in new and worn tire conditions. North American design. Approved for use on EPA SmartWaySM certified equipment and meets California's CARB requirements Sizes 11R22.5 11R22.5 275/80R22.5 11R24.5 11R24.5 275/80R24.5 Looking at the XZE2+ we see MI claims Outstanding resistance to high scrub applications from large solid shoulder. Exceptional traction throughout life of tire promoted from full-depth sipes in center ribs. Lower downtime and protection from bruises and penetrations fostered by full-width protector ply over the working plies. Improved resistance to curbing and sidewall scrub from raised curb guard feature Sizes 265/70R19.5 285/70R19.5 275/70R22.5 295/80R22.5 Now I am a bit confused why you are looking at these two lines when according to Michelin specifications they do not share a common size. But to be specific yes there is a major difference between these two lines. Size.

The XZE2+ and XZA are clearly not the same thing. Tread pattern, Tread depth are just two of the obvious differences. As long as you have decided on Michelin and not one of the other brands, I would be inclined to go with the one Michelin suggests for RV usage

Initially I just wired to the back-up light to test the system. Since I have a C and can see out the back window (have one of those special flat lens things) plus good rearview mirrors, having the distraction of a small monitor while driving isn't needed.

You didn't say if you were dealing with Michelin company owned store or independent dealer selling Michelin tires. The dealers may each have a reason to push one type over the other. I prefer to look at the corporate spec sheets as this is reviewed by Mich Engineers and represents the design intent of the tire. Looking at the MI spec sheet http://www.michelintruck.com/michelintruck...o.do?tread=XZA2 ENERGY I note the "Energy" tag for improved fuel economy and that Michelin suggests this tire for RV application http://www.michelintruck.com/michelintruck...o?tread=XZE2%2B Michelin does not clearly ID this design for RV application and no mention of better than normal fuel economy You didn't mention your size or Load Rating so you will need to look at the details.

I see back-up camera systems for RVs advertised for $300 to $1600. I have a Class-C and installed a Peak/Wireless back-up camera system with 2.4 in. LCD monitor for $80. It turns on whenever I shift to reverse and is wireless to the driver seat area. Not as big a screen as the thousand dollar units but it works for me. You can check the auto parts web sites to locate a store near you that has the unit. Now if you want the camera on full time you will need to run 12v power to the back of your RV but if you are only concerned when backing up this unit works just fine.

RJ I do not recommend mixing brands in a dual application even if the size is listed as the same there will be different deflection characteristics that result in one carrying more than it's mate. Since you have a GY and the rest are BS I strongly suggest you run the GY on a Front position or if you have a Tag axle with just single tires on each side that would be OK also. RE Riverwear. Can't comment on one brand tendency or not to develop this condition or not. It is a form of localized wear that goes around the tire but not side to side. Kind of meanders a bit. Lets see if this link works.

Wayne If you can't get actual corner weights then your approach would seem to be the best you can do. If your wear is OK then you are probably not too far off. You might touch base with RVSEF and ask what their schedule is. Never know if one of their guys will be traveling near where you expect to be. The only other option is to keep an eye out for a truck scale that has enough level space to allow you to do the multiple weigh that would allow you to calculate the individual corners. I have seen scales with enough side clearance to allow this. You first get the full axle weight then drive through again with one side on the scale and one side off then do the math. Hopefully there are some FMCA members who have had the corners weighed and are willing to share the data here. So far not so much.

Bill My goal is to develop statistical analysis to allow me to make a suggested adjustment for estimated load when individual corner weights are not known. I note that many folk do not know their actual corner loads and are unlikely to ge them as they do not attend large Rallies and Conventions where RVSEF or similar organizations offer the weighing service. However everyone can get to a truck scale and at least know their axle load. I am expecting to be able to say something like... If you do not know your side to side loads but only your axle load then If you estimate a 50/50 load split you have a xx% probability of overloading one of your tires by yy% If you estimate a 45/55 load split then.... and if you estimate a 40/60 load split then .... Initial data suggests that if you estimate at a 45/55 split and then inflate all tires based on the 55% load when using the tables you have a 25% chance of still having one tire overloaded. Note the 25% figure is NOT based on a detailed analysis of the data but is provided here as an example based simply on eye-ball look at limited date. To make the data analysis more reliable I need at least 25 more coach weights in Class-A plus 30 in Class-C. On another forum I am also attempting to address the question of side to side and axle to axle variation for 5th wheel trailers. Note I already have confirmed unbalance at more than 10% level for two Motorhomes out of 27 and confirmed unbalance axle to axle of more than 60% of 5th wheels in addition to side to side unbalance at about three times the rate found in Motorhomes. This preliminary data clearly supports the need for developing reliable prediction statistics to encourage more people to get their real corner loads or at a minimum to stop estimation on equal distribution. The above is a strong smoking gun for the probable root cause for the 18% tire failure rate seen in RV applications. I find it interesting that FMCA people seem to feel this is not something they need to worry about.

dbik86i Before you can increase the load capacity you will need to increase the inflation. Your wheels may not be rated for the higher inflation. They should be marked with a statement of max load and max inflation. It also sounds like you are assuming your tire failure was due to overload and not some other cause such as impact or puncture. Did you have the failed tire inspected by a Company Store, not an independent tire dealer? Did you ask for an adjustment from the Manufacturer? Manufacturers will only accept or turn down an adjustment AFTER an experienced engineer does a complete inspection. Note I said Engineer and not just a tire tech. I also wonder if the new G rated tire is a good match based on actual size of it's companion dual. If you had much more than 5,000 miles then there is a chance the worn F rated tire is smaller so you are asking the G rated tire to carry more load but probably don't have increased inflation for the increased load. If you have to I would suggest you move the fronts to the rear dual positions and put the mixed load tires F & G on the front to avoid the potential dual lading issue.