Which Tire is best

[CapriRacer]

Originally Posted by Top

The factor is 1.1 Thanks Capri Racer.

So for this Michelin P tire it is 2183/1.1=1984.5
The same load rating (adjusted) as a load range C LT 235/75/15 tire at 50 PSI.
Michelin used to make this tire as an LT load range C when it was the LTX M/S, but it was made a P tire when the LTX M/S2 replaced it. Not sure why exactly.

We've had this discussion before, but a P235/75R15 XL has the same maximum load as an LT235/75R15 Load Range C but at different pressures. (35 psi vs 50 psi). These are different animals, but the specs look similar.

Why the difference? Because P metric tires are designed to be flexible and LT metric tires are designed to carry high loads compared to the amount of material they use and the space they occupy, so the rubber in LT tires isn't very tolerant of flexing. I hope you notice that the P metric tire is on the large end of the P metric sizing range, and the LT is on the small end of the LT size range.

[Globie64]

Okay, so which would be better for a trailer, a P rated tire with more flex, maybe transmitting less vibration to the trailer, or an LT, with more load carrying... reserve?

[slowmover]

The "best" trailer tires (all trailer types) would be commercial service tires such as:

MICHELIN XPS Rib

and

BRIDGESTONE Duravis r250

Everything else is a step down, but the

BFGoodrich Commercial T/A

is a good choice, albeit at a lower price.

As the above tires are expected to roll a lot of miles in their life-time (where TT's generally don't), the difficulties start to show up as these are 16" tires (and A/S rides on OEM 15"). So for those not wanting to change wheel size, the MICHELIN mentioned in earlier posts are popular.

ST tires are about good enough for a trailer wihere the payload $$ value is low.

.

[CapriRacer]

Originally Posted by Globie64

Okay, so which would be better for a trailer, a P rated tire with more flex, maybe transmitting less vibration to the trailer, or an LT, with more load carrying... reserve?

First I think your premise about reserve is wrong. They have the same load carrying capacity, and the way the tire industry uses the term "reserve" (difference between rated capacity and the actual load), means there is no difference in reserve capacity.

But if you are asking the question, which tire is likely to have been more over-designed (which is the way the trailer folks are using the word), then I would have to give the nod to the P metric version - BUT - I think there is more to this.

First, the idea that P metric tires are better designed is just a feeling on my part and I don't have any substantial data to back it up. It's based on the idea that among the fall out of the Ford/Firestone situation was an examination by the tire manufacturers of how well tires were performing and passenger car tires on SUV's was given a lot of scrutiny - and that would have included this particular size.

Second, the order that these tires were looked was: 1) Passenger car tires on SUV's, 2) Passenger car tires on cars, and 3) LT tires. So I think LT tires would not have benefited from as long of time of scrutiny and therefore would not be as far along in the development process.

Third, I think the question of which is better is also dependent on what your intended use of the trailer is. If you are only using the trailer on highways and never in primitive campsites, then the LT metric might be better. But I would think that high speed runs would be better with the P metric tire.

[RLS]

Originally Posted by slowmover

The "best" trailer tires (all trailer types) would be commercial service tires such as:

MICHELIN XPS Rib

and

BRIDGESTONE Duravis r250

Everything else is a step down, but the

BFGoodrich Commercial T/A

is a good choice, albeit at a lower price.

As the above tires are expected to roll a lot of miles in their life-time (where TT's generally don't), the difficulties start to show up as these are 16" tires (and A/S rides on OEM 15"). So for those not wanting to change wheel size, the MICHELIN mentioned in earlier posts are popular.

ST tires are about good enough for a trailer wihere the payload $$ value is low.

.

There is a commercial 15" tire. It is the Continental Vanco 2, 225/70R15C. The C at the end stands for commercial. It will lower the trailer a little less than 1/2".

[switz]

Unfortunately, the letter at the end of a tire description is the Load Range rating of the tire, so the letter "C" does not mean commercial in the post above.

[CapriRacer]

Originally Posted by switz

Unfortunately, the letter at the end of a tire description is the Load Range rating of the tire, so the letter "C" does not mean commercial in the post above.

I am sorry, but in Europe, they use the letter "C" behind the tire size to mean a "Commercial" tire as opposed to a "passenger car" tire. In the US, we refer to these types of tires are "LT" tires, because of the letters in front of the tire size.

And in this case, the term "commercial" is used differently than when it appears in the name of the tire. If the term appears in the name of the tire, it means the tire was designed to be used in a commercial application and may contain long wearing tread compounds and a heavy duty casing (but don't quote me on that).

Let me give you some examples.

195/70R15C 104/102R 8 PR (Load Range D) Continental Vanco 2

LT235/85R16 120/116Q Load Range E, BF Goodrich Commercial T/A All Season.

You can look both of these up on Tire Rack's web site.

[RLS]

Originally Posted by switz

Unfortunately, the letter at the end of a tire description is the Load Range rating of the tire, so the letter "C" does not mean commercial in the post above.

This is a "D" rated tire, look it up

[r carl]

Originally Posted by Globie64

Okay, so which would be better for a trailer, a P rated tire with more flex, maybe transmitting less vibration to the trailer, or an LT, with more load carrying... reserve?

P rated tires will allow a trailer to go into a sway situation easier than a LT or ST tire.

[Lance M]

Originally Posted by r carl

P rated tires will allow a trailer to go into a sway situation easier than a LT or ST tire.

I'd like to see some test data that would support this. I'm not saying it isn't true, it just seems to be said, heard, or read, not tested.

[jcanavera]

Originally Posted by HiHoAgRV

I believe those of us that have 6 tires on the ground have an advantage...the weight per tire is low considering the mass of a 34' trailer. That make life for tires easier than, say, a 30' Slideout with 4 tires and about the same weight.

Knock wood, I've been happy with my Marathons.

Go_Navy,

I'm curious what brand of tires are on your trailer today. Are you replacing them due to wear or age?

The universe of 34' trailers is obviously smaller and quite honestly unless someone can note differently, the reports of ST tire failures seem to be much lower on the 34's than on the tandem axle trailers. As noted by HiHoAgRV, when you consider the load per tire, the 34' Airstream does distribute the load across 6 tires. Most of us who have the 30' or 31' model slide outs are probably carrying more weight per tire than any other Airstream built. I know my local dealer's employees all say that the 34' Airstream is their favorite to tow due to that 3 axle suspension.

Quite honestly I never had ST tire problems until I bought my 30' slide out. I've had belt slippage on two Maxis ST E rated ST's and had lost a good chunk of tread on a Marathon D rated ST. Both brands of tires failed after 3 seasons of use. I firmly believe that the high load factors and the ST tire construction shorten the life of these tires making them more prone to failure. I'm very careful regarding tire inflation and speed and I know for a fact that underinflation/speed was not a factor in any of my failures. The only saving grace is that the failures were detected in my driveway and not on the road.

Three years of life isn't comfortable in my situation and I bit the bullet and upgraded to 16" wheels and LT tires last year. Based on what I see here, that upgrade will probably prove out to be a good move. However if I were in your shoes, I really don't see the need to have to go the LT route at this point. As noted by others, there are a lot of satisfied ST tire users out there and while your 34' is large and heavy, it has the advantage of 6 tires to carry that load. That to me makes a big difference and I would seriously consider putting another set of ST tires on your trailer. As to brand, we all have our preferences. Again if I were making that swap, I personally would probably consider putting a set of major branded tire ST tires on.

Jack

[richinny]

Originally Posted by Top

I'd like to see some test data that would support this. I'm not saying it isn't true, it just seems to be said, heard, or read, not tested.

for what it is worth....
some 10 years ago i swapped a set of lt tires for p tires on a car trailer. the ride went from nice and stable to white knuckle driving. the fact that some p tires have softer sidewalls than others is also a factor. just sayin'.....

[Globie64]

This is all great information, thanks to all of you. I feel pretty good about my Bridgestone LT tires, have to be a ton better than what's on there.

[Ridgerunner3]

Originally Posted by Globie64

This is all great information, thanks to all of you. I feel pretty good about my Bridgestone LT tires, have to be a ton better than what's on there.

What size and Bridgestone LT's do you have?

[Globie64]

225 75 15, Dueler A/T 695

[dalemonroe]

I've used Continental Vanco 2 tires on my commercial van. They out wear the original Goodyears 3 to 1.

[dalemonroe]

Originally Posted by Go_Navy

Thanks. I will be keeping the 15" rims. So that part is an easy decision. I dont know which is better the LT or ST tires and frankly dont know anything about tires. I have read so many meandering posts about tires on this website..I was hoping for a pretty simple answer/recomendation on which brand and which type (LT or ST).

I've been told that ST tires have stronger side walls to deal with the extreme side forces when cornering with tandem or triple axels.

[CapriRacer]

Originally Posted by dalemonroe

I've been told that ST tires have stronger side walls to deal with the extreme side forces when cornering with tandem or triple axels.

There's debate about whether this is true or not, but one thing is clear. There are very few sidewall failures in ST tires not caused by road hazards. The real issue with ST tires is belt leaving belt separations, commonly called "tread" separations.

[Go_Navy]

Hi Ricky,
Thanks for your post. You may have noticed I also have a 34'. Can I ask what tires you have and if you are happy with them ...Thanks !

[oxblood]

Interesting! I've wished Michelin would make an ST tire as I have no confidence in Goodyear marathons for my 34' classic. What do you mean "weight rating on sidewall must be derated"?