Follow-up to tire purchase and tire balancing

[Tagalong]

Some of you may recall I began sometime last year to post about purchasing larger tires for our 34H Journey. I also, recently posted a question about the various tire balancing methods in use today. Here are my final choices. Remember, the sole purpose for increasing the size of our tires is to take advantage of being able to use less air pressure in a larger tire to result in a softer ride, especially on rough roads.
I will be having XRV255/80R22.5 tires dynamic (spin) balanced and installed on our Journey tomorrow. Here is how I arrived at my decision.
I read your posts on both inquiries on this forum and talked to lots of travelers who also made tire changes. Then, while at the Central FL State WIT Rally, I happened to sit next to Doug Formanek at one of the dinners. I asked him who I could have a “candid” conversation with regarding increasing tire size on our particular coach. Doug immediately gave me Steve Damman’s name. My first conversation with Steve was outstanding. We discussed tire specs and the “what ifs” of increasing tire size on my Journey. Our first conversation (and your suggestions) leads me toward the following three tires to choose from. The three tires are the; XZE255/80R22.5, the Good year G670 255/70R22.5 and ultimately the XRV255/80R22.5.
My second conversation with Steve, (just a day ago and after I gathered my support information)
I finalized my decision on both the tire selection and balancing method.
I really liked the increase in width and diameter of the XZE and the G670. However, given the fact that I have the Cummins 300hp engine, the much larger size of those tires may inhibit the efficiency of the engine/driveline. I know it will alter the speedometer but that is a non-issue. Although, there might be a tad bit less fuel mileage the bigger issue may be the power loss (moving larger tires) up long grades, such as out west.
I’m sure many of you with a better understanding of engineering might consider my above issues not so problematic; however I’d rather be more conservative in this case. In any case, when Winnebago began increasing the size and GVWR for gas coaches you’ll notice they installed the XRV235/80R22.5 tires on them. At the same time, they began installing XRV255/80R22.5’s on the 34’ Journey’s… without changing any aspect of the engine/driveline on the coaches, and I know they’ll fit (verified by Steve). The one specification that I paid particular attention to is the tire RPM’s. At first, I rationalized that a tire revolving slower will run cooler. But, conversely, a larger tire revolving slower will also require more torque. The 235 RPM’s are 556, the XRV255 RPM’s are 541 and the XZE RPM’s are 538.
Also, Steve had routinely attended Michelin seminars and offered other suggestions for me to consider. The XRV is truly built for RV use. Its compounds and construction is specifically designed for the type of “typical” driving a motorhome is used for, i.e. some long distance/short trips/storage. In spite of all the problems mentioned on the forums regarding “zipper” blow-outs, I had (I hate to admit it) seven years on my XRVs with little problems. We did have a blow-out on our right rear inner dually. Fortunately, the blow-out was 8 to 10 inches and didn’t destroy or damage the other dually or coach. The blow-out was clearly age related. When you think about all the research and information we digest, no matter which RV tire you like or purchase all tire manufacturers recommend one thing… at six years in service consider replacing them! I’ve even heard some tire dealers say the safe life of an RV tire is five years!
(Side note: While at the FL Central State WIT Rally we had “Chip” of “Rally-R-Us” install the “Saft-T-Plus” on our front end and last year I installed Koni FSD shocks.)
As for balancing the tires, Steve explained that Michelin does not recommend placing anything inside their tires that moves (even for a short duration) and can abrade the thin membrane Michelin adds to the entire inner surface to help maintain air pressure. Those of you with Aluminum (machined) wheels are lucky. If you install quality tires on those wheels you may not even need to have them balanced. I have the steel wheels with liners and they need to be balanced.
This post is written for informational purposes and not intended to suggest that one tire or balance method is better or worse or right or wrong. These are my opinions based on the specifics of our coach, conversations with experts and fellow RV owners and, more importantly, the driving/handling/ride we have experienced in our Journey for over 38K miles.
Thank you for reading this lengthy post. I hope some of you may benefit from some of the information offered. I plan to post a report on our experiences with the new tires after we’ve logged several hundred miles over various road surfaces/conditions.
Dave