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Krazyjohnny · 08-01-2013, 02:36 PM

This has been a very confusing and troubling experience riddled with multiple data points.

I am speaking of the MIchelin LTX MS2 in 235/75 R 15 XL

You have the load rating on the Michelin website of 1985 lbs for the tires.
You look at the "Load Index" which is labeled as a 108T and it tells you a weight of 2205 lbs per tire.
The tires themselves are labeled at 2183 at their max pressure.
Thank goodness my needs fall righ tin the middle. Just a little bit more info for others to use in making their selection.

RAH · 08-01-2013, 02:58 PM

My understanding is that the Michelin LTX MS2 tire is rated at 2183 per the sidewall. The 1985 figure is already derated 10% (i.e., divide 2183 by 1.1 = 1985)

Ridgerunner3 · 08-01-2013, 04:05 PM

My recently purchased Michelin LTX MS2 P235 75 15 XL tires have 2183 lbs stamped on the sidewall.

CapriRacer · 08-02-2013, 05:19 AM

Just a word of caution:

There can be side to side and front to rear variations in tire loading on a trailer. I have used 15% to account for this variation.

Andrew T · 08-02-2013, 07:48 AM

Hi Folks

I think you might be over thinking this a little.

Tire ratings are a function of application ply rating and size, so the worst quality tire and the best have the same load rating. On a Quality tire they test well beyond the load ratings.

Other than 30' Slide-outs and some 86-93 32' models I have never weighed a loaded for travel Tandem axle Airstream that was over 8000 pounds on the axles. We have at least 200 customers with 30 & 31' Classic trailers with 235 Michelins with several years of excellent results, we just don't get failures. Some of our original test units went 10 years without a failure.

Rich Luhr who has a 30' heavily loaded trailer and does substantial miles was averaging 3 ST failures a year. I beleive he still has the original 4 Michelins he installed 4 or 5 yers ago.

I am sure there are other 235 tires that will work but our track record is with Michelin.

The 16" Load Range E tires from the Eddie Bauer are also very reliable but they are quite harsh riding for the Airstream, we have switched several Eddie Bawers to smoother riding 16" tires.

I hope this helps.

Andrew T

Krazyjohnny · 08-02-2013, 08:12 AM

Andrew,

Thanks for your comments. This is all quite unnerving. You get to where you are almost manic on what is the correct answer. If the tires (Michelin 235/75 r 15 XL 108T) are truly sufficient according to their stamped on carcass rating I will go this route instead of spending $1400 + on new wheels and tires.

SteveSueMac · 08-02-2013, 08:42 AM

I'm going to say amen to krazyjohnny and Andrew T's advice. I'm officially converted and am going to opt for the 15s. I've reached out to my dealer to see if he'll install and if not I'll find a local tire outfit that (hopefully) will!

Krazyjohnny · 08-02-2013, 09:10 AM

SteveSueMAc,

I think our trailers are very similar so we should both have similar results. I was just quoted $704 out the door from my local Discount Tire store. It is only $100 different than the Goodyear Marathons. I think that is a very small price to pay for the peace of mind. Besides 16" Load range E tires are rated at 3K lbs each. That is a very rigid sidewall and I have had issues with my exterior skin cracking around the front storage compartment supposedly due to harsh towing conditions.

Ridgerunner3 · 08-02-2013, 09:17 AM

I switched from Maxxis load range D's to the Michelin 15's this summer. I have towed a few thousand miles with the Michelins and have been happy with the towing performance. Right or wrong, the Michelins give me great peace of mind while towing.

Airtandem · 08-02-2013, 09:29 AM

????? when having the tires changed, do they use jacks under the axles or do they use the ramp method? I have been told to NEVER use a jack on an A$.

Kosm1o · 08-02-2013, 09:46 AM

Quote:

Originally Posted by Andrew T

Hi Folks

I think you might be over thinking this a little.

Tire ratings are a function of application ply rating and size, so the worst quality tire and the best have the same load rating. On a Quality tire they test well beyond the load ratings.

Other than 30' Slide-outs and some 86-93 32' models I have never weighed a loaded for travel Tandem axle Airstream that was over 8000 pounds on the axles. We have at least 200 customers with 30 & 31' Classic trailers with 235 Michelins with several years of excellent results, we just don't get failures. Some of our original test units went 10 years without a failure.

Rich Luhr who has a 30' heavily loaded trailer and does substantial miles was averaging 3 ST failures a year. I beleive he still has the original 4 Michelins he installed 4 or 5 yers ago.

I am sure there are other 235 tires that will work but our track record is with Michelin.

The 16" Load Range E tires from the Eddie Bauer are also very reliable but they are quite harsh riding for the Airstream, we have switched several Eddie Bawers to smoother riding 16" tires.

I hope this helps.

Andrew T

Andrew,
I have been very happy with my. Michelin M/S tires (an LT tire) before they became or were replaced by the M/S 2's (a "P" designated tire) which came out about 2 years ago. Have you noticed any difference in these two tires?
Kos

gmw photos · 08-02-2013, 10:23 AM

This all got me to thinking and looking around at what might be available in 15" LT varieties. I found the following, in no particular order, beyond the already mentioned Michelins:

Continental Vanco. 235/70-15. 2470 lbs @ 65 psi
Good Year Cargo G26. 225/70-15. 2470 @ 65
Kumho Road Venture APT KL51. 235/75-15. 1985 @ 50
Pirelli Scorpian ATR 235/75-15. 2335 @ 65

.....so it looks like there are various options out there in different brands. Needless to say, each person needs to do their own homework regarding the weight of their own trailer, axle and wheel specific poundage loading.
I

CAT scales

switz · 08-02-2013, 10:33 AM

Are there any Canadian regulations that require the 10% derating of a passenger rated tire used on a trailer like in the states?

The US regulation below drops the Michelin LTX (P) 235/75R15 XL molded on the sidewall rating of 2,183 pounds (or 8.732 pounds for four tires) to 1,985 pounds (or 7,940 pounds for four tires).

49 CFR 571.110
Tire selection and rims and motor home/recreation vehicle trailer load carrying capacity information for motor vehicles with a GVWR of 4,536 kilograms (10,000 pounds) or less.

S4.2.2.1
Except as provided in S4.2.2.2, the sum of the maximum load ratings of the tires fitted to an axle shall not be less than the GAWR of the axle system as specified on the vehicle's certification label required by 49 CFR part 567. If the certification label shows more than one GAWR for the axle system, the sum shall be not less than the GAWR corresponding to the size designation of the tires fitted to the axle.

S4.2.2.2
When passenger car tires are installed on an MPV, truck, bus, or trailer, each tire's load rating is reduced by dividing it by 1.10 before determining, under S4.2.2.1, the sum of the maximum load ratings of the tires fitted to an axle.

S4.2.2.3
(a) For vehicles, except trailers with no designated seating positions, equipped with passenger car tires, the vehicle normal load on the tire shall be no greater than 94 percent of the derated load rating at the vehicle manufacturer's recommended cold inflation pressure for that tire.
(b) For vehicles, except trailers with no designated seating positions, equipped with LT tires, the vehicle normal load on the tire shall be no greater than 94 percent of the load rating at the vehicle manufacturer's recommended cold inflation pressure for that tire.

An interesting point is that per the 2013 Airstream Classic parts manual, all three models are all fitted with the same 5,000 pound rated axle. Thus the captioned tire lacks the capacity equal to or exceeding the axle rating.

When checking the 25' to 28' model Airstream axle ratings in the parts manuals, they share a 3,800 pound rated axle. Two of the captioned tires derated capacity would just exceed the axle rating with a value of 3,970 pounds.

The 30'+ Internationals and the 19' Bambi have 4,500 pound rated axles. Thus, even using the sidewall rating, two of the captioned tires lack the load capacity of the axle.

I would think that running with the trailer axle weights totaling 8,000 pounds means that the user is overloading the tires for US usage and is relying on Michelin's build in conservative rating because of better materials.

I do use the captioned tires on our 25FB International, but with our 1,200 pound tongue weight setup and not exceeding the GVW of the trailer, the maximum axle load could only be 6,500 pounds (6,100 + 400 pounds from the equalizing hitch) which does leave a considerable reserve load capacity in the tires.

I think Airstream pushes the four GYM ST tires hard on the 31"Classics that have a GVW of 10,000 pounds, average literature empty weights of about 7,300 pounds and literature average tongue weights of 790 pounds. Allowing for a 900 pound tongue weight and a 1/3 transfer to the axles, the tires are supporting about 9,400 pounds out of a total tire load capacity of 10,160 pounds. A user would have to be very load conscious if they used the captioned tires to not exceed their 7,940 pound derated axle load since the 31' Classics average about a 6,500 pound empty axle weight. The larger fresh water tank capacity uses a large junk of the payload at around 510 pounds including the water in the water heater.

I am not arguing that these tires do not work, but I am concerned about being at or over their rated capacity with the heavier trailers is a major decision the user has to make to assume that liability.

Krazyjohnny · 08-02-2013, 10:46 AM

Airtandem,

Read your owners manual and moreover here. I think you will find there is a specific place to apply the jack for raising the trailer. I have heard from several sources you are not supposed to jack via the axle on Airstreams.

Coaster · 08-02-2013, 10:49 AM

Quote:

Originally Posted by SteveSueMac

I'm going to say amen to krazyjohnny and Andrew T's advice. I'm officially converted and am going to opt for the 15s. I've reached out to my dealer to see if he'll install and if not I'll find a local tire outfit that (hopefully) will!

I went to 15 tires in may. discount tire put 4 tires plus a spare. I have taken two 1000 mile trips to carters lake since then. Im very satisfied so far. They also installed a dill tpms and I keep at 48 lbs. The pressure rises to 52 or 53 lbs underway. they have a smooth softer ride. wish you all the best

Luigi123 · 08-02-2013, 04:03 PM

For those running the Michelin 16"LTX on 30ft Airstreams what tire are you running loaded and or unloaded( empty tanks for transporting)? I am picking mine up over the week end and this important. Tire dealer filled them to 65 lbs. Appreciate any info here.

Luigi123 · 08-02-2013, 04:04 PM

That should have read, " what tire pressure are you running..."

Dean E · 08-02-2013, 10:50 PM

Quote:

Originally Posted by Pepthedog

All I know is I put a set of Michelin LTX 235/75R15s on and really enjoy the ride now. I had a Marathon fail but got stopped before it came apart totally and dodged the bullet. Now I don't even consider the gun loaded. Peace of mind goes a long way.

Hello all,
I would like to get a set of the Michelin LTX M/S2 P235/75R15s to replace the old set of ST205/75R15s. The 1984 vintage steel rims are 5.5 inches wide (measured with a set of calipers), but the Michelins are specified with 6.5 inch width, and suitable for a range of 6-8 inches.
I assume that because my old 5.5 inch width rims are outside the 6-8 inch range for the new Michelins, the handling would not be right, and that there would be too much wear at the center of the tread.
I am disappointed because I don't want to go back to the ST design.
Thanks for all of the detailed and reasoned info!

Lance M · 08-03-2013, 06:11 AM

Quote:

Originally Posted by Luigi123

For those running the Michelin 16"LTX on 30ft Airstreams what tire are you running loaded and or unloaded( empty tanks for transporting)? I am picking mine up over the week end and this important. Tire dealer filled them to 65 lbs. Appreciate any info here.

Luigi,
Have you read this thread? It is probably the best place to find the answer to your question or have your question answered. That specific question comes up often on that thread. There are a lot of different answers.

Lance M · 08-03-2013, 06:17 AM

Quote:

Originally Posted by Dean E

Hello all,
I would like to get a set of the Michelin LTX M/S2 P235/75R15s to replace the old set of ST205/75R15s. The 1984 vintage steel rims are 5.5 inches wide (measured with a set of calipers), but the Michelins are specified with 6.5 inch width, and suitable for a range of 6-8 inches.
I assume that because my old 5.5 inch width rims are outside the 6-8 inch range for the new Michelins, the handling would not be right, and that there would be too much wear at the center of the tread.
I am disappointed because I don't want to go back to the ST design.
Thanks for all of the detailed and reasoned info!

Dean,
I would recommend the Continental Vanco 2 215/70/15 LR-D
Great tires in my opinion.