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**Rocinante** · 12-10-2015, 09:49 AM

Posting to ask about a "new" 15- inch tire from Michelin that looks quite promising. It is the Michelin Defender LTX M/S P235/75-15 109T XL.

Caveat: I don't know that it's actually a new tire, but I've not seen it before and a search of Airforums threads on this tire comes up empty.

This one has the same "T" speed rating as the Michelin LTX MS/2 P235/75-15 108T XL. Key difference seems to be that the Defender 109T is rated at 2271 lb, vs. the MS/2 108T, which is rated at 2205. So, after the 10% de-rating exercise the new tire comes in at 2044, which gives a bit more buffer.

Anyway, it looks promising. Anybody out there already running this tire? Would love to hear your thoughts.

dznf0g · 12-10-2015, 10:05 AM

I believe this is a relatively new tire, and have heard that is it the eventual replacement for the LTX M/S2....kind of like there was an overlap of availability of the LTX M/S and the LTX M/S2. Not sure if anyone here has tried the Defender, but I think the differences are a non- issue, other than a bit of load improvement.

**Rocinante** · 12-10-2015, 10:25 AM

Thanks, Rich.

We're thinking the same thing - it seems mostly the same tire with a slightly higher load capacity. This may be exactly what we need in a 15" tire for our 27FB. Nobody local has this tire in stock, but they all say we can special order. When we're ready to replace our GYMs, we'd love go this way vs. up-sizing to 16" wheels.

KJRitchie · 12-10-2015, 10:33 AM

What I don't like about these 15" tires (I have the Michelin MS2) is to get max load you have to run them at maximum 50lbs pressure while the 16" tires you can safely run them from 65lbs to 80lbs and get adequate load. But then its cheaper not to have to mess with purchasing new rims.

Kelvin

SteveSueMac · 12-10-2015, 10:35 AM

Kelvin - what problems do you see at 50 PSI? We use the Michelin 15s at that PSI and have no problems at all. In fact, I wouldn't dare run them lower for fear of overheating them or losing my "capacity cushion".

dznf0g · 12-10-2015, 11:36 AM

With Michelin, at least, I have found no noticeable difference in ride or trailer treatment between 70 psi, 75psi or 80psi. I have 16" LTX M/S and have settled in at 80psi. I would have to believe the Defender will have similar non-harshness at full pressure.....but that's a supposition on my part. I had 15" LTX M/S2 XLs on my van (sold today!) and there was no noticeable difference either, between full pressure and something lower.

**Rocinante** · 12-10-2015, 11:44 AM

Just got off the phone with Michelin, because I could not find this particular tire on their website. It's on Tire Rack, Discount Tire, etc., but not theirs.

Turns out this tire is scheduled to be available in March of 2016. That must also be why it shows as a "special order" item for most retailers.

So, I guess we'll hang tight until March!

KJRitchie · 12-10-2015, 12:19 PM

Quote:

Originally Posted by SteveSueMac

Kelvin - what problems do you see at 50 PSI? We use the Michelin 15s at that PSI and have no problems at all. In fact, I wouldn't dare run them lower for fear of overheating them or losing my "capacity cushion".

You just have to be more vigilante in checking the tire pressure. I use a TireTraker TPMS system which gives me some piece of mind. I also carry a Viair pump. The 16"s are just a little more forgiving in load cushion in case you had a slow leak and you had to travel some miles to get a repair.

Kelvin

Al and Missy · 12-10-2015, 04:38 PM

I'm not sure these are really Light Truck Tires; the information available now is not consistent. The manufacturers are not clearly delineating light truck tires from passnger tires rated for light truck service. Michelin calls them LTX MS2, but one site say they are available in p-metric and lt-metric sizes, another uses different terminology. Tire rack says they are Service 109T, Michelin says 108T. Both say that the load range is XL. According to Tire Rack, load range XL is a p-metric description. If the tire were LT-metric, the load range would be C, D, E, etc. The issue, to me, is that by FMVSS, the load bearing capacity of P-metric tires used on a truck or trailer must be de-rated 10%. 2271# /1.1 = 2064# which is 75# more than the current P225/75-15 LT tire.
If they had been available a year ago, I might have bought them instead of upgrading to 16's. But then my trailer only grosses to 6300#. On a 7800# 27' trailer, maybe not.

Al

DoublTrouble · 12-10-2015, 04:42 PM

Rocinante,
I looked online at tire rack this morning. 128.20 but on backorder. I also find these intriguing since I'd like to switch from GYMS but wasn't excited about switching to 16s. 27FB axles rated @ 3900, these tires look promising. I'm sure that someone will beat me to them...
That's okay, please share with the rest of us. Thanks. ..

white laker · 12-10-2015, 05:01 PM

I have a 2002 31 Classic that has a five year old set of 15 inch Michelin LTX M/S 2. The tires are starting to show their age so before I head back to Ottawa from Florida I want to change out the tires. This isnt about the lower cost of the tires in the states. Just look at the exchange rate! We are thinking about a new or newer A/S in the next couple of years so I really dont want to put 16 inch tires on and then trade it in if I dont have to. Based upon the spotless history on these 15 inchers on the trailer over many thousands of miles, I would like to hold off untill these new tires become available. We typically pack light and run all tanks dry while towing. These tires do have a greater margin of safety so I think that I will hold off until we head back home and see if I can get a set. Any constructive thoughts would be appreciated. Thanks Pete

TheCabin · 12-10-2015, 06:09 PM

This discussion is way too positive for an AS tire thread. What is wrong with this tire?

gtc6452 · 12-10-2015, 07:08 PM

follow

SteveSueMac · 12-10-2015, 07:23 PM

Quote:

Originally Posted by TheCabin

This discussion is way too positive for an AS tire thread. What is wrong with this tire?

😂
Good one!!

switz · 12-10-2015, 08:00 PM

This new 15" Michelin tire, even with it's higher derated capacity than the current 15" Michelins, would still not be useable on our Classic where all but one of the four tires is carrying over 2,040 pounds.

But this new 15" model would be a good choice even for the 7,800 pound 27FB Eddie Bauer models. It will be a natural for our 2015 23D International Serenity in the future when it is time to retire the new 15" Michelins put on in July 2015.

I will hazard a guess that Andy at CanAm will recommend the 44 psi he suggested for our 2013 25FB International Serenity for the new tires as well. We are using 44 psi on the 23D and the Dill TPMS is showing good numbers running down the highway.

subfan1 · 12-10-2015, 11:18 PM

Darn, still not enough capacity for our 20 FC

switz · 12-11-2015, 07:16 AM

The 14" GoodYear Marathon ST215/75R14C tire is rated 1,870 pounds @ 50 psi and is 26.7" in diameter.

The 15" GoodYear Marathon ST225/75R15D tire is rated 2,540 pounds @ 65 psi and is 28.3" in diameter.

The existing 15" Michelin LTX (P) 235/75R15 XL tire is sidewall rated 2,183 pounds @ 50 psi but has to be derated to 1,985 pounds for trailer use and is 28.9" in diameter.

The 16" Michelin LT225/75R16/E LTX M/S2 tire is rated 2,680 pounds @ 80 psi and is 29.2" in diameter.

When we switched from the stock 14" GYM tires and wheels on our 2015 23D International to the 15" Michelins mounted on 15" SenDel T03-56545T wheels (matches the 16" SenDel T03-66655T wheels on our Classic), we raised the trailer 1.1" higher off the ground and increased the load capacity 125 pounds per tire. We run the 15" Michelins at a lower pressure of 44 psi.

When we switched the stock 15" GYM tires to the 15" Michelins on the 2013 25FB International Serenity, we raised the trailer about 1/4" in height using the factory wheels. Camping ready, the 25FB had less than 5,900 pounds of axle weight. We ran the Michelins at 44 psi per CanAm recommendation.

So the 16" tire is less than an inch taller in diameter which raises the trailer just under 1/2" in overall height and also increases ground clearance by that amount. The hitch would be looking for the tow vehicle ball to also be about 1/2" higher for the trailer to sit level.

The switch to the 16" tires for the 20' single axle trailers provides a small increase in load capacity as well as a tire that has had a better service history. One can find a 1/2" taller shank for the ball on the tow vehicle without too much problem.

The left photo is a 15" GYM on the left with a 15" Michelin on the right with both mounted on the stock Airstream wheel.

The right photo is a 15" GYM on the left with a 16" Michelin on the right with both mounted on the appropriate wheels.

Tireman9 · 12-11-2015, 07:44 AM

Don't forget the MAX operating speed for ST type tires, unless specifically marked on the tire is 65mph.
65 is not an average but ever as damage to tires is cumulative and just as putting air back in a tire that has been run flat does not "fix" it, running 55 does not "fix" the damage you did by running 70 and putting the burnt hot dog back in the refrig doesn't "fix" the hot dog.

Lucky Dog · 12-11-2015, 08:48 AM

Quote:

Originally Posted by Rocinante

Just got off the phone with Michelin, because I could not find this particular tire on their website. It's on Tire Rack, Discount Tire, etc., but not theirs.

Turns out this tire is scheduled to be available in March of 2016. That must also be why it shows as a "special order" item for most retailers.

So, I guess we'll hang tight until March!

I had the same experience in November. Found one of the OEM Goodyears wearing badly (curb side rear), had the "alignment" checked and was told no problem there and probably a bad tire. Decided to go with the 15" Michelin. Checked Tirerack, saw the new Defender but unavailable. Went to my local tire guy, Michelin dealer and he said same. Called Michelin and they also gave me the March 2016 timeline for availability. Not wanting to wait, went with the 15" LTX MS2 so many on the forum are using. Took 2 in at a time, mounted, balanced, metal stems, out the door for $607.76/4 plus sent in the $70 rebate (online) offered from Michelin. All four manufactured 40th week, 2015. A great deal as far as I'm concerned and kept the $$ local.

Lucky Dog · 12-11-2015, 09:06 AM

Quote:

Originally Posted by KJRitchie

What I don't like about these 15" tires (I have the Michelin MS2) is to get max load you have to run them at maximum 50lbs pressure while the 16" tires you can safely run them from 65lbs to 80lbs and get adequate load. But then its cheaper not to have to mess with purchasing new rims.

Kelvin

According to the Tire Tech page on Tirerack explaining Maximum Load, the load carrying capacity on the P-Metric XL tire is all in at 41psi. If I am interpreting that correctly, perhaps that is why it was recommended to Switz to run at 44psi. All the load carrying capacity there plus a little extra to stiffen sidewall further? On the scales, my 25FB ready to camp was just under 6000lbs. So I feel pretty good to be rid of the Marathons and have plenty of reserve load capacity with the de-rated XL Michelins. Will probably run at 45lbs unless the tire engineers jump in to say run the max inflation pressure of 50. Would have liked to try the Defender with the slightly higher load rating but wasn't willing to wait any longer while running on the Marathons!