tireman9

Sorry, I still don't see where a GY 295/80R/22.5 with 5250# load needs 125 psi.

Only comment I have about selecting tire brand is to check on the number and location of truck tire service centers they have. Hopefully you will never need warranty or other special service but if you do I would not want the nearest dealer 500 miles away.

All that means is that there is extra rubber under the bottom of the groove to the top of the steel belt. In some applications such as City Bus where wear is very poor due to all the turning they can cut more grooves in the tire to improve traction without having to buy a new tire. Sorta like retreading in that you get more miles out of the carcass. I would not regroove a tire for normal highway (RV) use.

Well if you were driving say 80 to 100k miles a year and wearing tires out it might make sense BUT if you get a flat you may end up needing a special tow off the Interstate as you might need to wait a couple of days to get a replacement. The cost of change over is prohibitive and the cost of replacement before you wear the tire out could raise your expenses too. Since RVs are not carrying load for $$ based on maximizing load capacity the weight savings and fuel economy improvement isn't there for normal RV use.

Wayne, Sorry I didn't see your question earlier. Had a couple of projects here at home that kept me away from the Internet. Anyway. When looking for Load & Inflation tables I would go with the ones found with the tire companie's RV information as for some tires they may have special requirements such as speed limitations and sometimes slightly different loadings. For Goodyear I go with information and links on THIS web page. and the download shows for a 295/80R22.5 with 5,250# per tire the Front (single) inflation needs at least 80 psi and the rear (dual) need 90 psi minimum. Now I suggest you add 10% (10 psi would be easy and acceptable) to these Minimum inflations to allow for day to day Ambient temperature changes that could result in the need for a trip to the Truck inflation station (too much work when on the road). This way you would have plenty of advance notice of the need to add a few psi and still have plenty of margin in your tires. Now the suggested 125psi you found is considerably different. Where did you get that information? Can you provide a link?

x2 What Brett said

I think the reality is that the 19.5 & 22.5 "TBR" (Truck-Bus radials) are designed for nominal 100,000 mile life and one or more retreads while LT type tires for more like 40 - 60k miles and no retread. I would expect the "life" of a "TBR" to be greater as long as both tires were run with similar load margin (15% to 20%) of max.

I have a 23' Class-C with LT 225/75R16 LR-E tires A comment on the topic of rolling change and moving the two fronts to one side of the drive axle: While it is well established in the industry that tires that are a dual pair need to matched in OC to be within 3/4" of each other and that it is many times a good idea to replace the mate of a tire that suffered a road failure, I have never seen anyone suggesting that if one tire on a rear axle that has duals on it fails, then all four tires need to be replaced or at least matched in OC. If anyone is aware of such information I would appreciate it if the link could be provided so I can correct my thinking. I may act like I know it all but I am certain there are things I don't know. That's why I keep Brett around

Well I guess I steped in it now. I suppose it could be argued that there is no way to provide information that will not cause confusion because no everyone has identical rigs. It would be nice to ask people to use my and other suggestions as guides and not as absolutes. The logic behind my three year rolling change was two-fold. One to lower the sticker shock many were complaining about when confronted with buying 6 tires at one time. In some case I think this probably resulted in a few waiting another year or two before getting new tires. Not always a good idea. The 2nd thought behind the rolling change was to keep newer tires on the front when possible. Now to the specific observations. The start of the rolling change at 7 years would result in tires being changed at 7,8 & 9 years. It may be better to start the change sooner on your first set of replacement tires. If you keep your RV long enough to need to consider a change of the 2nd set that would mean you have a 12 to 16 year old RV. At that point there are a lot of other things that need replacement so tire expense is just one part of the costs. Lets look at the size difference between opposite sides of the rear axle. The difference between the fronts and rears on the first year of change would be minimal asa both have 5 to 7 years use on them depending on when you start the rolling change. I haven't measured annual tread wear but this will vary depending on miles, tires used and driving style. On the 2nd year of course we would have 1 year old tires on one side of the rear and 7 year olf tires on the other. The big question is how much tread has been worn off. I would think that for the majority of tires there might be about 0.10" worn off the new tires and maybe .30" worn off the old tires. This is a 0.20" difference on the radius or 0.62" on the circumference of a tire with a circumference of over 100". It is important to remember that tires wear fastest in early life and slower as time goes buy so you can't do straight line estimates for tread wear. So we are looking at less than a 1% difference. Maybe someone could check my assumptions and math and also address if a 1% side to side difference is meaningful in a differencial.

Well I have to admit that I felt who could do a better job of taking care of their tires than I do? I installed the tires new when they were only 18 weeks old. I installed TPMS and white tire covers in the 1st month of RV ownership. I inflated them to +15 to +20 psi over the minimum needed to support the measured load on each corner of the RV. (My RV was very lightly loaded and Brett can tell you how small is was). I have kept my travel speed down to 60-65 range. Never drove the RV below the inflation needed to support the load. Never drove in Southwest and maybe the hottest I ran into was in Oregon the couple weeks after Redmond. I had intended on following my own advice and do a "rolling" tire change (2 tires each year) starting at 7 years and selling the used tires. BUT when I dismounted the tires to remove the original internal TPM sensors, I discovered that one tire from a dual position had severely stress cracks at the edge of the tread & sidewall so it had to be scrapped. The cause for the cracks was a slow leak last winter in it's mate resulted in it's mate to carry excess load, I believe that if I had used the RV I would have have discovered the low tire, fixed the problem (leaking valve core) and it's mate would never have been overloaded. My main mistake was that I was over confident and didn't do the detailed inspection I should have done on the overloaded tire as it had what I thought was adequate air. Clearly just looking at the tires while still on the RV, I had missed the cracks (outside edge of the inner dual). I clearly was over confident about the condition of my tires because of my care and that over-confidence lead to a less that complete, off the vehicle and even dismount inspection. Because of my experience and looking at the costs of having a dismount inspection done every year I would suggest that people consider doing a "rolling change" starting at the 6th year of use for their tires. and if either tire is a dual position ever looses significant inflation both tires need a dismount inspection. I have a blog post on the Rolling Change process. Now some will have some problems if they have special wheels or more than one size on their coach, but if you review the post I think you can develop a plan that will work for you. Along with the purchase of 2 tires a year you can be sure to at least have an off vehicle inspection completed as a minimum as it will be much less expensive to address any issues discovered than rather than when on the road.

OK Quick re-cap. The 315/80R22.5 M144 specs rim width of 9.0 - 9.5 so I would not use that tire on an 8.25 rim. Toyo has a 12R22.5 in a M170 design that does fit your rim. You only gave the total unit weight so we can't do any calculations to confirm capacity or Load Range needs. This information would be good to have. Now for mixing tires: Front axle. Both tires should be same size / Brand / Design / & inflation Drive All 4 tires should be be same size / Brand / Design / & inflation PLUS each pair of tires in dual need to measure within 3/4" OC of each other when fully inflated but not loaded so probably moving the current tag tires to one side of duals will work or maybe better. Move the two fronts to the drive dual position and put two new tires on your front axle. Tag Since this is free rolling it really just needs to be same size tires and same inflation Be sure to record the full size, design and DOT serial for each tire while doing all the switching around. Let us know when you calculate the corner weights for each axle of the RV so we can confirm your proper Cold Inflation Pressure "CIP"

Saw the question this AM and wrote a reply, then had errands to run. I must have shut down computer before hitting the SEND. Give me about an hour and I will re-post the info.

Joe. A quick review leads me to believe that the XRV 295/80R22.5 size is a discontinued item as it does not show up in the on the Michelin web site for the XR applications. This reinforces the question of the real age of the two tires you have on your coach. I did find two items in the 295/80R22.5 size in the Load Inflation table page. The XZA2 Energy in LR-H & LR-J The Specifications show an OD of 41.3 I didn't find a 295/75R22.5 in the Michelin line but looking at Bridgestone and comparing their 295/80R22.5 LR-H R268 has an OD of 41.6 and their 295/75R22.5 LR-G has an OD of 40.3. These two tires have Max load capacities of 7,830 @ 125 and 6,175 @ 110 receptively so are not "all the same" Clearly you now know more about tires than your tire dealer. Now before you can move forward you have some homework to do. 1. Confirm the size, Load range and design for all your current tires. 2. Learn and record the full DOT serial, including the 4 digit Date Code at the end of the serial 3. Get your RV weighed. Ideally this means the actual load on the end of each axle. Michelin, Goodyear and Bridgestone all have published information on how to do the calculations, but if you can't do that at least the individual load on each axle Let us know what you learn and then we can provide a more informed suggestion for your next action.

Skipped over this first time around. Not sure what you mean when you are talking about "trailer tires". While a majority of travel trailer tires of "ST" type come from China that is not 100% true. I understand one large mfg, Maxxis, is not made in China. Now if you are talking large Truck/Bus radials i.e. 19.5 and larger rim then that claim is certainly not true. Many TBR tires are identified for their intended application. Some for fronts, some for drive, some for trailer and some "all position". I have not read about any general trend for TBR size "trailer" tires to be made in China. In fact I am pretty sure some are made in the US. Note I do not have access to all production data and am not sure if I have ever seen tire type by country in a published manner.

Vibration that comes & goes... My vote is Balance and /or run-out. Do run out first as you can balance a cinder block. Run out can be more than just the tire as pointed out. centering on hub is easy to mess up when re-mounting tire & wheel on the RV. Once you know run out is OK then I vote for on-vehicle spin balance as hubs and brakes can be out of balance. While I don't recall ever seeing a rotor balance weight coming out (its a metal slug driven into the cooling vane of some rotors) it is always possible.

Yup, That's why you want to get the OC measurement with the tires inflated and when comparing tires be sure both have same psi. Sorry if I wasn't completely clear in the above psots about measuring inflated tires. Sometimes I forget that others don't do things I consider "automatic". Down side of having a lot of experience.

If Brett's suggestion doesn't provide an answer You might need to look at alternate brand tires for the coach. If you go that route it is suggested that all tires on an axle, especially the front, be the same size, brand, design, Load Range and carry the same CIP based on the measured load on the heavier end of that axle. I further suggest a +10% on the inflation so you aren't running the minimum needed.

Correct. It is very difficult to accurately measure OD but OC is relatively easy. You don't need to match front tires other than it is suggested they be marked as the same size, brand, Load Range and design, and inflated to the same PSI based on the heavier axle end. Each pair of tires in "Dual" application in addition to being same marked size, brand, design, load range and inflation need to have their OC measures and confirmed to be +/- 3/4" OC of each other. Yes a brand new tire will grow a bit so if I had to match a new and warn pair I would want the new tire to be smaller and closer in size. Usually duals should be replaced as a "set" of two tires but this is not always possible if you aren't running a fleet of trucks.

I'm not aware of any rating numbers or stars or letter grade that cover tires from different companies. BUT I would consider all tires of the same size & Load Range that carry the "Smartway" rating to be essentially equivalent and better than tires that don't have the EPA rating. Just as "your mileage may vary" when talking about car fuel economy the same goes for TBR tires but at least these large tires have been separated into two catigories. SmartWay and not SmartWay.

A review of the tire Load - Inflation charts would tell you when you need to increase your inflation by the next 5 psi incrament. BUT it is generally recommended that you use the heaviest expected loads for your basic minimum inflation. You should probably not be playing a game with lowering inflation to the bare minimum needed to carry the load. Personally I prefer to see people have a minimum of 10% extra load capacity with 15% or greater being better. Most car companies have a "reserve load" (excess capacity) of 13% to 20%. Currently I suggest: Weigh the corners of the coach when it is at its heaviest. Consult the tables to learn the MINIMUM inflation needed to carry the load on the heavier side of each axle. Consider that pressure to be the MINIMUM you should ever run. Set your TPM warning to that pressure not 10% or 15% below the minumum Your CIP should be at least the minimum + 10% and as long as you don't exceed the max for the tire or wheel you would round up to the next 5 psi increment. Ensure your digital pressure gauge is accurate to +/- 2 or 3 psi. I have covered gauges and how to do the calculations in a number of posts on my RVTireSafety.com blog

I would be careful about any claims for any performance characteristic made by any individual tire company. Its all to easy to claim Our tire is better when you don't really know what the other tire is that they are using as a reference. Now for Fuel Economy there is a rating that all tire companies can apply for. EPA Smart Way I think a good question to ask your tire dealer is "Do your tires meet these standards."

Not sure what your exact question is. The dimensions and load capacities at the stated inflation are very similar. What is your measured load on each side of your rear axle?

While there are many posts on the difficulty many are having finding the specific brand & size they want, shortages are not always limited to a single brand or a line or size. Some general guidelines to keep in mind when shopping for other options. You can mix brands on a vehicle. If doing this, you should still keep the sizes the same or very close to the original size and Load Range. You should not mix tires on front axle. BOTH should be same tire.(i.e. brand or size or type or design or Load Range) You should not mix tires in a pair of duals in addition to being the same brand or size or type or design and Load Range, you need to match the physical OD within 1/4". I have a couple of blog posts showing how to properly measure the OC to meet the measurement goal. How to match duals and How to replace duals. Mis-match size can result in a tire wearing out in a couple thousand miles or even a tire failure due to load imbalance. While it is possible to have the left pair of duals a different brand or design than the right side duals this is not a desirable situation but some times there is no alternative.

Ran Firestone Transforce HT 16" for 28,000 miles (7 years). One of 6 had sidewall stress crack @28k (long term parking during Winter) so it needed to be replaced. Many / Most Firestone & Bridgestone LT and TBR tires made in one of two plants in USA. Similar tires (BS or FS) would most likely be made in same plant to almost identical specifications.

You say tire pressure is "OK". I assume you mean you know the load on the tires and have enough inflation to carry the load. What Cold Inflation Pressure do you use? What are your actual loads for each corner or for each axle. The 2 body plies is actually more than what many have in their LR-E LT type tires as in my experience 1 ply is used in many tires of this size. How many miles on the tires? I would give them 500 mi to get all the mold lubricants off the surface. What speeds are you talking about?