Fifth Wheel Trailer Tires

[Scottybdivin]

I just replaced 6 brand new Power King Towmax ST's with Michellin XPS Ribs. It never left my driveway with the China Bombs except to head over to Discount Tire. My technician that did the PDI with us suggested I get rid of them ASAP. I listened. I probably got them a lot cheaper than they would have charged for them, and I watched them being mounted and balanced by professionals.

[mstan]

I have a 2005 36' carriage carrilite. 15K3. When I bought this trailer new little did I know how much tire and wheel trouble I would have. They came with the G614 Goodyear tires. First of all i had a tire that uncapped. Like it was a re-capped tire. Tore up the whole side of my trailer and the wheel well. Tire pressure was set at 110# as per max load. (Goodyear finally owned up to a problem in a bad run of tires.) Then next trip on a fuel stop I checked all of my tires as I aways do. Noticed that one tire was low. Filled it with air and was puzzeled as to why it was low. I had only traveled about a hundred miles. Got to our camp site and noticed it was low again. Refilled it and then noticed I could hear a air leak. Discovered after removing the wheel and tire. that the aluminum rim had a hair line crack in the middle of the wheel. Replaced the rim. I checked all the rims to make sure that they were truely G rated rims. (yes). I then purchased TMS to keep a closer eye on the the tire situation. over the course of the next 3 years I have replace 3 more rims with the same problem. So I ditched the aluminum rims and purchased steel rims thinking now my problem is solved. I just got home and have a damaged trailer again! G614 tires Two of them failed again. The tires are 3 years old. I keep them covered and treated. I always run them within 5#'s of max air. At 400 + bucks a tire I think that with reasonable care they should be good. I am off the Goodyear train from here on out.

[Greytraveler]

Just got back from a three week trip with our Arctic Fox fifth. Talked to several fifth owners while staying in various campgrounds. More than one has switched to Michelin LT tires, which are made in USA if they are the same E rated tires as on my truck. Without question my next set will be Michelin.

[azdryheat]

Regarding the Goodyear 614's: I'm curious why folks here pump them up to 110 pounds? Is that necessary? At 110# they are rated for 3750 pounds each for a total load capacity of 15,000# for 4 tires.

Goodyear's load capacity chart shows that the normal load of 3042, what our E's are rated at, requires only 80# of air. Then why 110?

The chart and other info is here: http://www.goodyear.com/truck/pdf/edb_loads.pdf

[FastEagle]

Originally Posted by azdryheat

Regarding the Goodyear 614's: I'm curious why folks here pump them up to 110 pounds? Is that necessary? At 110# they are rated for 3750 pounds each for a total load capacity of 15,000# for 4 tires.

Goodyear's load capacity chart shows that the normal load of 3042, what our E's are rated at, requires only 80# of air. Then why 110?

The chart and other info is here: http://www.goodyear.com/truck/pdf/edb_loads.pdf

None of the 2008 Everest models came with tires rated at 3042# at 80 psi.

Your question about tire load inflation and proper tire pressure is complicated unless you have some knowledge on why, and how, load inflation charts/tables are used/applied.

Let’s say the certification label on your Everest says it came with ST235/80R16E tires and they are rated at 3420# and the recommended tire pressure is 80 psi. Replacement tires need to equal or exceed that certified requirement. The LT235/85R16G tire can be a suitable replacement. It’s called “plus sizing”. Using the proper load inflation table for that tire would require it to be aired to at least 97 psi to insure it equaled the load capacity of the Original Equipment tires.

FastEagle

[Scottybdivin]

Maybe the weight ratings are much more conservative on LT's due to carrying passengers and higher speeds. A LT235/85 16 XPS Rib weighs 56 lbs. A Towmax STR235/80 16 weighs 38 lbs. Yet the Towmax is rated for 3420 @ 65 mph max. The XPS have a speed rating of 106.

[FastEagle]

Originally Posted by Scottybdivin

Maybe the weight ratings are much more conservative on LT's due to carrying passengers and higher speeds. A LT235/85 16 XPS Rib weighs 56 lbs. A Towmax STR235/80 16 weighs 38 lbs. Yet the Towmax is rated for 3420 @ 65 mph max. The XPS have a speed rating of 106.

The two brand name tires you have mentioned are completely different in design and construction and are tested on their individual qualities. One is designed for the automotive industry and the other exclusively for the trailer axles. A closer study of each design will reveal a lot about it’s weight, especially if you compare the equal sizes such as ST235/85R16E to the LT235/85R16E.

FastEagle

[wingnut60]

Tire discussions are always interesting, and many times they approach the excitement of synthetic oil vs fossil; exceeding tow ratings; Chev vs Ford vs Dodge. I just got the Nov issue of Trailer Life and in the RV Action Line column, there is a complaint of tire wear on a 2010 Nash fifth-wheel trailer. Specific conditions of this complaint aside, the reply by a Matt Turley at Northwoods Manufacturing, was as follows: "With 12,000 miles on any trailer tire, depending on conditions, the tire is on the upper end of its life expectancy..." You can read the full article on pages 12 and 70 of the Nov TL magazine. This is a weird statement, in my opinion. I hate to think that no one should expect much more than 12,000 miles out of a set of trailer tires, but this guy thinks so.
Joe

[RustyJC]

Originally Posted by FastEagle

The two brand name tires you have mentioned (Michelin XPS Rib and Towmax) are completely different in design and construction and are tested on their individual qualities. One is designed for the automotive industry and the other exclusively for the trailer axles. A closer study of each design will reveal a lot about it’s weight, especially if you compare the equal sizes such as ST235/85R16E to the LT235/85R16E.

FastEagle

More accurately, Michelin classifies the all-steel construction XPS Rib as an "all position tire". That means it can be used on steer, drive or trailer axles. Because of their all-steel construction and extremely long life (80,000+ miles is not unusual), they are frequently used by oil field hot-shot rigs both on the trucks and the tandem dually gooseneck trailers. And, yes, this information regarding their classification came from Michelin's Technical Support group.

Rusty

[FastEagle]

Originally Posted by RustyJC

More accurately, Michelin classifies the all-steel construction XPS Rib as an "all position tire". That means it can be used on steer, drive or trailer axles. Because of their all-steel construction and extremely long life (80,000+ miles is not unusual), they are frequently used by oil field hot-shot rigs both on the trucks and the tandem dually gooseneck trailers. And, yes, this information regarding their classification came from Michelin's Technical Support group.

Rusty

Rusty, it is a misnomer to refer to a truck tire designed for all positions as a trailer tire. In the trucking world there are three distinct terms (sometimes four if you count directional) used for tires designed for use on those axles. Drive & Steer which are pretty self explanatory. The “All Position” term describes a tire as being suitable for the drive, steer and sometimes “Tag” axles. Of course those tires can be used on the trailer axles when they meet the requirements the vehicle manufacturer has certified for the individual vehicle.

I think the misrepresentation of the term “All Position” comes from reading tire manufactures data books about tires they build for the motorized RV community. Sometimes their literature is very misleading and strays from industry standards.

Michelin Americas Truck Tire Position Page

FastEagle

[RustyJC]

Originally Posted by FastEagle

Rusty, it is a misnomer to refer to a truck tire designed for all positions as a trailer tire.

The Michelin Technical Support representative explicitly stated that Michelin recommends the XPS Rib for trailer service where the size and load rating meet the trailer's requirements. This, of course, WOULD be the case where the OEM tire was an LT235/85R-16 load range E rated 3042 lbs (single) @ 80 PSIG. Many 5th wheel manufacturers (specific example - my previous 2000 Jayco Designer XL 3610RLTS) utilize the LT235/85R-16E as the OEM tire - my Jayco came equipped with Goodyear Wrangler HTs which I replaced with the XPS Ribs.

Following is the specific reply I received from Michelin regarding applicability of the XPS Rib as a trailer tire:

Thank you for your email. We welcome the opportunity to serve you.

Obviously the utilization of the XPS Rib tires are limited, as they are only manufactured in 16" sizes, LRE (10 ply) versions. It is an all steel radial casing design and strength, making it long lasting, durable and also retreadable. In its class nothing better, excellent for a commercial trailer tire.

The only drawback (we see you are in Houston) it is NOT an all season tire. The XPS Rib is highly recommended for your application!

Mike T.
Michelin North America
Consumer Care Department
Certified Michelin Product Expert

Rusty

[azdryheat]

Originally Posted by FastEagle

None of the 2008 Everest models came with tires rated at 3042# at 80 psi.

Your question about tire load inflation and proper tire pressure is complicated unless you have some knowledge on why, and how, load inflation charts/tables are used/applied.

Let’s say the certification label on your Everest says it came with ST235/80R16E tires and they are rated at 3420# and the recommended tire pressure is 80 psi. Replacement tires need to equal or exceed that certified requirement. The LT235/85R16G tire can be a suitable replacement. It’s called “plus sizing”. Using the proper load inflation table for that tire would require it to be aired to at least 97 psi to insure it equaled the load capacity of the Original Equipment tires.

FastEagle

Putting 97# of air in a tire that is labeled for 80# max is not a good idea.

The LT that I am running on the Everest calls for the max pressure of 80# for a max load of 3042#, which will support my two 6000# axles. If I were to be running the 614 tires and only needed to support my two 6000# axles then, according the load chart the tires would only need 80#, not 110#, to carry the load. Inflating the 614's to the 110# maximum is for a load of 15000#, which is 3000# more than is needed for 2 6000# axles. So why would I need to inflate the 614's to 110# when they only need 80# to do the job?

[wingnut60]

Several reasons come to mind: the tire will run cooler, will last longer, will produce less drag, in my opinion. In over 46 years of running light trucks and towing trailers, whenever I ran less than the sidewall max inflation pressure, I ended up with edge tread wear that did not occur if run at max psi. Your results may vary...
Joe

[ntrsandman]

We had Carlisle 235/80r16 lrE on our Fuzion when new. Previous experience made me look for replacement tires before first trip. Considered the G614. Some research showed that the G614 was not much better than the Carlisles and replacement tires of that size are not readily available at tire dealers if an emergency required it. We went to 17.5" tires and wheels. GY G114.