XL or C tires?

[switz]

Goodrich has the same 1985 pounds @ 50 psi on their webpage as in the Michelin webpage.

[AldeanFan]

Is there a difference or benefit to running a P rated tire at 41psi vs a LT tire at 50psi, as long as you don't exceed the weight limit of the tire at that particular PSI?

Also is there a benefit to inflating a P rated tire beyond 41psi?

[switz]

I doubt Michelin's webpage is in error if the actual tire has a 50psi side wall maximum pressure and a stated load of 2183 pounds. The foot note in the tire rack page picks two pressures for discussion, not the maximum pressure nor the maximum load capacity.

[switz]

Michelin does not provide pressure = weight capacity table for this tire. I put maximum pressure for maximum load just you do on the GYM ST tires or the 16" LT tires Airstream sells. I would not use 41 psi and expect tire to carry full load.

[handn]

I tow with Michelin P 235 R 75 XL tires on my 6300 gvw 2004 25 Safari. I inflate to 50 lbs. I am on my 3rd year with about 7500 miles.
I tow fast, about 70 mph, hot, one long road trip in 100+ weather and around curves and down steep downgrades in the mountains. I make lock to lock U turns and don't baby the tires in any way whatsoever.
Zero problems and no visible tire wear. The ride is so much smoother than the E rated ST tires I used to use.
If there is a practical difference between these tires and C rated LT tires of the same size, it escapes me.

[CapriRacer]

Originally Posted by switz

Michelin does not provide pressure = weight capacity table for this tire......

How about asking for one? Or make it simple, ask them what the load carrying capacity is at 41 psi.

[Phoenix]

On our 2008 Tundra, when the OEM tires wore out, I replaced the P (passenger) tires with E-rated LT tires, in the same size. You can really tell the difference in ride and handling at the same inflation pressure.

I used to run the P tires at 44 psi, which was the maximum printed on the sidewalls. When first installed, I ran the LT tires at 45 psi; and there was much less squishing around in the turns. The P tires made our pickup ride like a boat, actually like a really soft-sprung luxury sedan (like a Cadillac); and the LT tires hold a straight line better and don't feel squishy.

I now run the LT tires at 55/65 psi (front/rear) when towing, as those P tires always looked under-inflated.

Obviously, there is a big difference between P and LT tires; and this comparison probably does not accurately reflect the difference between C and XL tires. However, please note that we now have LT tires on our Bambi.

[SteveH]

The more air pressure you put in any tire, the more weight it will handle and the more stable it will be on the road. The tire rated for more pressure in a given size will carry more weight, at that max pressure.

If you air an "E" rated tire to the pressure of a "C" rated tire, it will carry no more weight than a "C" rated tire, and if you don't believe me, check the charts.

I don't know how it could be any more simple.

[AldeanFan]

Originally Posted by SteveH

The more air pressure you put in any tire, the more weight it will handle and the more stable it will be on the road. The tire rated for more pressure in a given size will carry more weight, at that max pressure.

If you air an "E" rated tire to the pressure of a "C" rated tire, it will carry no more weight than a "C" rated tire, and if you don't believe me, check the charts.

I don't know how it could be any more simple.

This is true up to the maximum capacity of the particular tire. For expample, adding more than 50psi will not increase the weight capacity of a C tire beyond 1985LBS.

My question is, is there a benefit to using an LT tire over a P-XL tire for a trailer, assuming either tire has an adequate weight rating for that particular trailer.

[switz]

Many of the choices in the 15" tire world will more than safely carry the load of many Airstream models. The 16" tire choices provide more weight capacity for more money (requires 16" wheels as well as tires). One must do some measuring to ensure the 16" tires will not rub the wheel enclosure on the specific trailer in mind.

Many folks float percentages and margins like they were the official word. The trailer axles have a built in safety margin at GVAW. Good tires have a built in safety margin at the weight shown on the sidewall. These margins might be small, but on tires for instance, does every one have a precisely calibrated tire pressure gage? So did we really inflate a tire to 50 psi or was it 48 or 52?

Each individual has to decide how much "safety factor" they want in their tire ratings, tow vehicle payload capacity, axle ratings, "stuff" in their trailer etc. Then they have the opportunity to live with the consequences of their decision.

[ROBERT CROSS]

"Many folks float percentages and margins like they were the official word. The trailer axles have a built in safety margin at GVAW"

Careful, blanket statement......your 2013 does.
....but our Classic, not so much, two 3500lb axles on a 7300lb GVWR trailer.

Bob

[r carl]

Originally Posted by SteveH

The more air pressure you put in any tire, the more weight it will handle and the more stable it will be on the road. The tire rated for more pressure in a given size will carry more weight, at that max pressure.

If you air an "E" rated tire to the pressure of a "C" rated tire, it will carry no more weight than a "C" rated tire, and if you don't believe me, check the charts.

I don't know how it could be any more simple.

Dont put a P rated tire on a trailer.

[Kosm1o]

There are many, many here that would say don't put an ST tire on a trailer.

[ROBERT CROSS]

There are many, many here who would say you need to do whatever they
have already done.

Bob

[SteveH]

There are many, many here that would say don't put an ST tire on a trailer.

Dont put a P rated tire on a trailer.

So, what does that leave you with???? Hmmmm?

[AldeanFan]

Originally Posted by r carl

Dont put a P rated tire on a trailer.

Why not?

I've read not to use ST tires, not to use LT tires, not to use P tires.

How did my trailer survive since 1977?

[switz]

The 2013 25FB Int'l has two 3,600 pound rated axles and a GVW of 7,300 pounds. The factory sales literature mentions a tongue weight of 833 pounds. The reality of our system is a tongue weight of between 1,150 and 1,175 pounds. When the trailer is not attached, the tandem axles are supporting up to 6,150 pounds at GVW, well below their rating of 7,200 pounds. Also the tires are supporting only that much weight, which is way below either their sidewall rating or the derated capacity.

[RLS]

Originally Posted by switz

The 2013 25FB Int'l has two 3,600 pound rated axles and a GVW of 7,300 pounds. The factory sales literature mentions a tongue weight of 833 pounds. The reality of our system is a tongue weight of between 1,150 and 1,175 pounds. When the trailer is not attached, the tandem axles are supporting up to 6,150 pounds at GVW, well below their rating of 7,200 pounds. Also the tires are supporting only that much weight, which is way below either their sidewall rating or the derated capacity.

You can also subtract the weights of the tires, wheels and brake drums

[Phoenix]

Just my opinions, to be taken with a grain of salt:

* I had P tires on an old SOB that caused the trailer to wobble and oscillate. However, this may have been caused by switching sizes (old size no longer available) and changing tire pressures. However, they were too spongy/springy and amplified road irregularities. In contrast, the triple axle trailer that came with our 27-foot cabin cruiser had P tires on it; and they worked fine and aged out after 20 years! (It now has ST tires on it.)

* Two different brands of ST tires (GYM and Maxxis, 225/75x15) had tread separation on our 19-foot Bambi, and therefore I don't consider most ST brands available on the market to be reliable. However, if Michelin made an ST tire, I would probably have tried them instead of buying 16-inch wheels and tires.

* LT tires and 16-inch wheels may be overkill on your Airstream, but 16-inch wheels make more tire brands and models available (although, in LT sizes).

* The Michelin XPS Ribs (225/75x16) are almost certainly overkill for our 19-foot Bambi. However, after numerous ST tire failures and damage to our Airstream, I was willing to pay about anything to stop the tire problems. With about two years and 15,000 miles on these tires, we have had absolutely no problems; and we no longer worry about tire failures.

The above being stated, the final decision is still up to you. Finding the right tire (at the right price) for your Airstream can be a trial-and-error experience, based on how much you travel and how much you have in your budget. Or, you can go the overkill route and spend more, but possibly save some time and repairs to your trailer in the future.

Unfortunately, buying tires is kind of like the old Fram oil filter commercial, "You can pay me now, or pay me later" (see below).

==============

Old Fram oil filter commercial, circa 1981:

1981 Fram Oil Filter Commercial - YouTube

[r carl]

Originally Posted by AldeanFan

Why not?

I've read not to use ST tires, not to use LT tires, not to use P tires.

How did my trailer survive since 1977?

I would not put on st tires either. LT is the logical choice.