Michelin LTX LT 235/75-15

[Dave Park]

The cars may be the same, but they're definitely NOT THE SAME!

European cars have completely different PCM programming, emissions requirements, use different fuel of a much higher octane rating than the crud Americans get served up, and so on. European versions of cars get better fuel economy, handle differently, run cooler...

Is it a surprise that a car that can tow 1000 lbs in the US can tow 3500 lbs in the EU when it's being run on 104 octane fuel?

[Bluto]

No matter what brand you like or dislike. If you run a tire not spec'd for the weight and application and temperature and speeds you'll have failures.
A lot of people like to bash the manufacture and it's easy to climb on board that train, but mgf. use the specs to tell us how to use the product safely, if you choose to go under rated, beware.
There is a lot of hearsay about blow outs on trailers that someone else just bought. Just buying a trailer and having having blow outs on a certain brand means nothing. Some questions I would ask are: How long was that trailer sitting on the lot with the tires exposed to Ozone before the trailer was driven? How fast and for how many hours was the trailer going when the blow outs occured? Did the blowout happen because of a piece of scrap cut the tire? Did the valve stem fail? Was the tire over inflated, under inflated?
No one tells us that stuff.

[JackMac]

Hello to all ---

Interesting thread, and to add something else, I have heard from good sources that in this part of the country, if highway patrol/police see car tires on a trailer, you will be forced to get it off the road and replace the tires with ST tires. I'm sure you will not be stopped just to see what kind of tires are on the trailer, but if something else happens, the legal aspect could be dire.

[RLS]

This is from another forum:

Posted: 07/11/10 06:24am Link | Quote | Print | Notify Moderator HwyExplorer wrote:

Update: I've just read on another forum and I've learned that actually the local highway laws may prohibit the use of anything but an ST tire on a non [COLOR=#0072BC ! important][COLOR=#0072BC ! important]passenger [COLOR=#0072BC ! important]vehicle[/COLOR][/COLOR][/COLOR]. So I guess I'm stuck shopping for ST's, but the question still is radial or bias ply


Not so. Someone is spreading false/incorrect info. We have one member that has been spreading this type of mis info.
There is no fed law that says you have to use a ST tire on a trailer. There are no state laws pertaining to such as states enforce fed laws.

Here is what NHTSA/DOT says about choosing tires;
49 cfr 571 tire and rim selection.
S4.2.2 Tire load limits for multipurpose
passenger vehicles, trucks, buses, and
trailers.
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 [COLOR=#0072BC ! important][COLOR=#0072BC ! important]passenger [COLOR=#0072BC ! important]car[/COLOR][/COLOR][/COLOR]
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.

As you see nowhere does the reg say a specific tire type such as a ST or LT or P is required. Only the weight capacity.

[2airishuman]

ron...

it's not my desire to post negatively about any specific shop,

especially one so apparently DEDICATED to it's unique approach ...

but i can say that i've communicated with a couple of customers

who suggest they were "talked into" using some components they'd rather not have used and can't easily UNdo.

________

what u kids do north of the boarder is not by concern really,

it's suggesting THAT APPROACH is OK to USE in the lower 48.

and MOST who follow the magic towing approach BUY into an entire set of conditions, tweaks and behaviors...

that NO ONE ELSE can or is willing to duplicate.

and the folks following the "go slow, PAY to change a lot of bits" approach really DO all seem happy about it...

i met a guy towing a 34 with a caddy

who was THRILLED with only traveling 100 miles per day and taking 30+ days to cross ocean to ocean.

but it's ONE shop in an entire industry,

which is VERY MUCH like going to one health guru who does things NO ONE ELSE in the profession supports.

i have also gotten UNsolicited commentary from state park rangers...

who FREQUENTLY see seasonal canadians enter their parks

with rigs that BARELY look stable at 20 mph.
_________

MUCH of this use of compromised towing vehicles relates to FUEL COSTS, i get that.

and there is ONE GUY here who regularly sings the PRAISE about towing with a small minivan....

but fails to mention his "TOWING" is only about 10 hours PER YEAR.

yes, ALL the details matter.
__________

the CONSPIRACY theory regarding ratings is often suggested...

"underrated to boost sales of something else" or "liability causes them to UNDER rate a yaya..."

there is of course NO PROOF of this conspiracy...

and upon digging one will find...

the axles, bearings, springs, gearing, drive shaft, exhaust, fuel management, frame, unibody or TIRES...

account for the lower rating (or some other critical bit that is NOT engineered for towing stresses)

there is ALWAYS some component which is the weak link or lowest common rating factor...

the fallacy and TRAP is that folks think changing ONE BIT solves the limitation when it doesn't.

that's why reinforcing the receiver or shortening the overhang is NOT a complete solution.

but conspiracy theories are SO APPEALING...

and offer SIMPLE blanket explanations where boring old engineering TRUTHS or details put folks 2 sleep.

so it's very hard to disprove a conspiracy,

and when DISproofs DO exists, the theorists just move to ANOTHER angle on the theory...
__________

it may be one world and the web might make life ALL seem to be the identical

but small differences really do matter.

a monkey and a donkey and a human all have basically the same genetics right ?

so how about a blind date with someone 99.5% similar?
_____________

i'm not drinking ANyONES kool-aid (including goodyear)

but i do accept the notion that MOST tire calamities can be traced...

to a known or UNknown user abuse or error.

curbs, wheel chocks, pot holes, UNDER inflation, scuffing, prolonged parking or AGE, and so on.

_________

as just ONE EXAMPLE of this, consider the following...

IF one tandem tire is UNDER inflated or removed for a flat

and the trailer is towed more than 50 miles with the other tire OVER LOADED...

BOTH TIRES are due for replacement, not just flat/leaking one.


and how many folks buy 2 NEW tires for each solo flat,

even though NOT doing so means towing on a SPENT (now defective) tire ?
_________

it's my understanding, the op is looking at 30/31 modern CLASSICs which have gvwr approaching 10,000 lbs.

that's up to 9000 on the axles or 2250 lbs PER TIRE of CONTINUOUS LOADING with intermittent loads much higher.

so suggesting that a tire rated for INTERMITTENT LOADING to 1900 lbs

(and much LESS continuous loading) is an OK/wise choice...is simply foolish.
_________

no offense intended toward ANY folks using these tires.

just don't rationalize the choice with conspiracy theories or possibly poor performance by OTHER tires.

cheers
2air'

[Gene]

That auto and truck manufacturers have tow ratings that seem inflated does not mean tire ratings are not correct. This analogy would be the same as saying some people may lie, therefore all people lie. Tire ratings are standardized, truck tow ratings have not been.

A C, D, E or any other rated tire will support a certain amount of pounds when inflated to a certain psi regardless of who made it. The tread may fly off or the tire may ride rough, but it will be able to do what it is rated to do.

So, I disagree with the statement: "I don't believe you can 'always' rely on just the numbers to make a choice." I am sure a C rated tire will roll along for a while and in some cases, for quite a while, but if it is rated for a lessor load, I'd pay close attention to that. The stress on the tire from a load for which is not rated would seem to result in a shorter life and possibly a greater instance of catastrophic failure (i.e., a blowout). Perhaps a 60,000 mile tire (Michelin does rate tires like that) may only last 30,000 miles.

It was also said "many" people use C rated tires on loads that are higher than the tire rating. Use of the term "many" or "some" is many times used by writers trying to prove a point without the facts to back up the assertion. I'm sure many people would agree with that. My guess is that very few people use C rated tires when the recommendation of tire companies is to use D rated tires. Because of the low instance of C rated tires being used, reports of failures would be very small (perhaps those "many" people would be too embarrassed to report a tire failure making reports 0).

Gene

[2airishuman]

Originally Posted by CrawfordGene

... I'm sure many people would agree with that...

i certainly DO...

appreciate those folks reporting/responding to the original question, actually using the mich' tire.

please others that are USING this tire, don't be intimidated by our banter...

_________

but i suspect those folks using that tire (many/most/all)

have made this compromised choice IN ORDER to keep the 15 inch rims...

so let me REposition and suppORt that claim with a question...

?? if the mich' ltx in the 15 inch size was AVAILABLE in a higher load capacity (comparable to Dz)...

which tire would you choose, the ~C or the ~D version??

cheers
2air'

[Andrew T]

We started experimenting with 235/75R x 15" Michelin LTX Load Range C tires on tandem axle airstreams 10 years ago. They have been to Alaska Mexico and everywhere in between. We have installed them on well over 100 trailers to date.

We simply never have trouble with them, I cannot think of anyone that has had a flat tire, they don't go out of balance like travel trailer tires do within 1 year. They have substantially more traction when breaking espessially in the wet and if you ride in the Airstream they are consderably smoother which will help your Airstream to last longer and loose fewer rivets.

Don't beleive everything you read about load ratings LT tires have to meet a much higher standard than travel trailer tires. If travel trailer tires were subject to the same level of testing they would have a lower rating than the LT tire. To put it another way if you kept overloading the tire until the point of failure the LT tire would carry considerably more weight than the trailer tire before failing.

Andrew T

[Road Ruler]

Originally Posted by Andrew T

We started experimenting with 235/75R x 15" Michelin LTX Load Range C tires on tandem axle airstreams 10 years ago.

We simply never have trouble with them, I cannot think of anyone that has had a flat tire

Sounds good to me. We are due to replace our P/XL trailer tires. These Michelins sound like the way to go.

[Andrew T]

Actually there are better size options for your 23'. Call me before you change them.

Andrew T

[Road Ruler]

Will do....thnxs Andy.

[2airishuman]

yeah no flat tires is impressive.

do they have some built in avoidance system for nails, screws and road debris?

there are at least 3 ways to process that info...

1. blindly accept it
2. blindly reject it
3. ask questions about it (not the same as questioning it) before moving to #1 or #2...

so here are a few of the relevant questions...

--100+ units...thats < than ONE per month over ten years...

? and what % of the 10s of millions are rvs in north america ?

? or what % of the 100s of millions of TIRES in use on towables ?

--10 years, so MANY of those should be on their 2nd or even 3rd set...

? or do these tires DEFY longevity issues too ?

--so some have been to alaska and mexico...

? how many 1-2 ? or all of them and again without ANY flat tires ?

--the gym ST tires on my unit (14 total tires) never had 'balance issues' in 100 of thousands of miles...

? UNeven wear is CAUSED by im-balance, alignment issues during use, so which came first ?

--make the airstream last longer...

? if this tire improves LONGEVITY on new trailers, why doesn't a/s use them ?

--while i would agree P metric and LT tires are more rigorously tested...

? where is the EVIDENCE that st tire testing for LOAD is based on LESSER standards ?

again...

? why doesn't A/S use them and where is the official ENDORSEMENT from mich' for this application ?

--the claim is made that these ~C rated passenger tires hold up BETTER under load than ST tires...

?? where is the proof, testing or basic tire industry EVIDENCE to support that claim ??

? where is even ONE bit of proof outside the 'user/vendor report' ?

--if these ~C rated tires are so great with loads OVER their ratings...

? why aren't they in use (by ANY COMPANY) on mid size SUVs or TRUCKS with axle/tire loads of 2000-2500 lbs PER TIRE ??
__________

other than sharing the background i see no evidence for any of the claims...

and "we started experimenting..." is the key concept in this entire issue...

experimenting on a PERSONAL trailer is fine, but on customers trailers...

that's just ONE more thing folks need to THINK ABOUT...before drinking the koolaid

cheers
2air'

[Aage]

Yer sounding like a #2 guy there, 2air...

Were you a-waitin' fur an expensive study team made uP of perfessers, mary-Anne, and Gilligan, with zillions of milez o' Dock-U-mounted research paid four by some YOU-knee-varsity to publish a paper on it in Lancet er sumpin?

I'm gettin em becuz they NEBBER ware oot! (not! where did he say Dat?)

Don't hold yer breth on dat, but DUE have a drank!

[Andrew T]

Hi 2 Air

I am just trying to be helpful here. But let me try and explain it better.

Out of 100 trailers with Travel Trailer tires we would see substantial numbers of units with shifted belts, out of balance condtions and a lot of flat tires. Lock the brakes up one time on ST tires and you can wear the tread off right to the cords. If you are working in a shop seeing hundreds of units the difference in reliablity is so obvious you cannot miss it. Most other shops won't see this because I doubt 1% of the RV stores have tire balance equipment. As well Airstream is the only RV that I know of that comes with balanced tires. Most other rv's see a fraction of the miles that Airstreams do so any tire will do.

I would ask how do you know you did not have any balance issues in your 14 tires? Did you actually check the balance on them every year or 2?

Airstream installed 7.00 x 15" Michelin LT tires as an option from 1971 to 1984. Today if they use a tire outside the industries minimal standard they have to redo all the brake certifications which would be far to expensive to do.

I have a copy of the standards for tire testing in print in a file cabinate somewhere but I cannot lay my hands on it right now but the difference is striking. One thing I do remember is trailer tires are tested to 65 MPH and a LT tire is tested to 75 MPH but I have been told Michelin and several other companies test theirs to 90 MPH.

I have a lot of customers that I know well who enjoy trying new things that are well thought out. I always explain the risks and rewards. The fact that we are the only dealer that mentions it is likely because we are the only ones that try these. There is no industry funding or initiative to try and find better tires. In fact in the cheaper trailers the biggest tire innovation in the last 10 years was that they could get $20.00 bias ply tires from China.

Now about loading, the heaviest 30 or 31' classic that I have weighed had 7620 lbs. on the axles. The 4 Michelins are rated for 7940 lbs. so they are close to their limit but not overloaded. Yes changing to 16" rims with 225 /75R x 16" tires does give more leeway, they look good as well and they have a slight edge in handling. On the other hand you are talking about a significant difference in cost and a harsher ride in the trailer.

Andrew T

[Road Ruler]

Mr. 2air... An informed decision is a priority here when it comes to tires. Although it may appear I made an on the spot decision your eyes have deceived you.
I doubt you ever worked for a major tire company. I spent a few years working for one and picked up a crap load of valuable info.
My last choice for a tire on my Stream would be an ST tire.

[2airishuman]

yep, gyms were rotated regularly and balanced as needed...

the balance change VERY little and wear was adequate so i've stopped checking now.

with disc brakes and centramatics REbalancing now is just not an issue.

but i'd never suggest anyone else take that path.

i doubt MOST trailer tires are handled in 'rv shops'

mine for example were only taken to goodyear shops where balancing gear IS available.

it's nice to think the 'difference' is equipment or skill or experience or willingness to try creative options.

but the primary difference is LIABILITY, shops in the u.s. don't "experiment" with good reason.

they'd have an impossible task justifying "experimenting" and would have little or no support from the industry if/WHEN trouble happens...

again, has mich' supported this application?

it's bad advice to suggest folks NOT living in canada tow with UNDERrated tires or vehicles...

that's really the issue and while it takes a LOT of effort for someone from texas or cali

to visit your place and get welded/lowered/shortened and so on...

tires can be purchased ON LINE by anyone.

a GOOD tire shop here would NOT mount an underrated tire IF they knew the application...

just like they wouldn't mount 285 width tires on 7 inch wide rims...

the china reference is misplaced, especially since the majority of gym ST failing tires were manufactured in canada.
________

aage, u crack me up!

and lancet (or the bmj) have done studies on single malts, cuban cigars and pasties so a TIRE study isn't too outta line...

Originally Posted by Road Ruler

...I doubt...

there is nothing in my post based on your note.

cheers
2air'

[CapnTom]

I found this on a tire website knowledge data base about tires for a trailer...it says not to use LT tires on a trailer...

Trailer Tires
Trailer tires are built to carry heavier loads than automobile tires, but they are specifically built for trailers. Don"t mount them on your car!
Trailers are more susceptible to sway, so they tend to swerve and destabilize while on the road. In large part, this is because of the less sophisticated suspension systems designed for trailers, but it also has to do with the heavier weight that trailer tires endure. Trailer tires must be built especially strong to manage much heavier loads than typical passenger or light truck tires. The requirements for trailer tires are unique, and their bias ply construction is specifically designed for strength.
Your car uses radial tires, which are built to hold steady traction in all sorts of driving and weather conditions. For cars, the sidewalls must be very flexible so your tires can maintain a good grip on the road. Automotive radial tires are great for your car, but because the sidewalls aren"t stiff, they can"t carry really heavy loads.
Trailers on the other hand, do not have any driving torque applied to their axles. They don"t careen around turns or weave in and out of traffic. Trailer tires only need to maintain traction when the driver brakes to stop or slow down.
In this case a stronger, bias ply tire is more necessary than a flexible, radial tire. Flexible sidewalls would create even more trailer sway and instability. Bias ply tires are constructed with cords woven across the tire from bead to bead. They also have consistent ply at the tread and sidewalls. This construction technique creates stiffer and stronger sidewalls, giving trailers the robust support needed to keep from swaying and destabilizing on the road.

[2airishuman]

SOME of that quote is sensible but some of it is also very dated and a bit misleading.

modern radials can and do carry as much or more than bias ply tires...

the materials and designs are simply better and stronger while being lighter and more durable.

the misleading part is that the weight isn't carried by the sidewalls (unless it's an airLESS or runFLAT tire)

the load is carried and the resistance to sway are BOTH based on air pressure.

higher pressures or the CAPACITY for higher pressures carry the load...

the materials and design of the tire need to be UP TO the task of the higher pressures,

just as the valve stem and RIM must be up to the task...

they are called PNEUMATIC tires for a reason, the LOAD is riding on air...

the part about trailer loads vs auto load is true,

and another significant issue is "sustained loading" as seen on trailers...

vs "intermittent loading" seen when cornering, turning or braking in a car/truck.

that's just another reason why one cannot directly compare st load ratings to p/LT load indexes...

cheers
2air'

[JakeSpoon]

With Load Range C Michelin LTX's, my primary concern is sway. Those who are running 235/75-15 LTX's, have you noticed more sway than with the previous tires?

[2airishuman]

the folks REPORTING so far are BOTH using hitches designed to ELIMINATE sway ...

there is NO sway with either of those hitches (pp or haha)

in fact this specific approach to hitching can HIDE poor setup issues that would be OBVIOUS with lesser hitches...

(and i'm NOT suggesting either of their rigs are set up poorly)

cheers
2air'