Tires: Driving 70 - 75 MPH - LT or ST?

[caissiel]

You don't get decent warranty with STs anyway. Why would anyone worry about LT warranty. LTs are rated for passenger carrying vehicles while anything can pass for trailer application.

[JIMNLIN]

JIMNLIN, you need to read my post #62.

I've read it.
And my reply was a email from Michelin that they will give a full warranty for their tire on a trailer. I have emails from other LT tire makers saying the same thing.

Here is a copy of the warranty that applies to vehicles without mileage warranties. Read the section for “what is not covered”. If your trailer has OE tires that were described as ST tires on the tire placard there are zero LT Michelin 16” tires that have enough load capacity to equal or exceed the load capacity of the 16” ST tires.

I've read it before and no where does it say what you posted.
What it does say is misapplication...
which a LT235/85-16 E at 3042 lbs capacity on a 5.2/6k axle is not a misapplication.
Now we can play your silly word games , as your well versed in, and back a LT mfg into the liability corner and sure they will not recommend a LT E with 3042 lbs capacity to replace a ST E with 3500 lbs capacity...... but why do you want to do this ??
In the mean time we still get a full tire warranty for a LT tire on our trailers just like we always have for many many years.

[Onstar20]

Originally Posted by lanerd

Why is it not safe? If everybody stayed with the flow of traffic, everybody would be doing 85 mph trying to keep up with those who drive like that. Those staying withing the laws, tend to keep the flow of traffic at a more reasonable speed. NOT safe? I don't understand the rational behind this statement. Don't other drivers have eyes and can see that you are going slower? Don't they have brakes so they can slow down if necessary? Can't they pass you in the left lane if they don't want to slow down.

Now if you are only referring to single lane (each way) highways, then I seriously doubt if the speed limit will be 70 or 75.

Many states, including mine, have a 55 mph speed limit for any vehicle with three or more axles or pulling a trailer/car....so they (the truckers) shouldn't be doing 70 or 75 any way. My 50 years of driving experience tells me to stay within the laws that were designed for the safe travel of those using our highways.

For the OP, safety should be your first concern. If the mfg specifically states that their ST tire is only rated for 65, you should take that as fact. Just because "you read somewhere" that you can go 10mph over" should not be taken seriously unless it comes from the tire mfg itself.

I, personally, would stay within all speed ratings whether it be from the tire mfg or state laws and recommend you do too. If you disregard these ratings, I would go with a more safe tire that would be within the ratings.

Ron

Absolutely totally agree 100%
BTW, Trailer Tires, ST Tires vs LT Tires vs Passenger Car Tires ~ The Right Tires for your Trailer

https://www.youtube.com/watch?v=r6SwwRnmp1Q

[timetogo]

The following is typical of several brands of ST tires.

All Power King TOWMAX
®
tire lines are warranted against failures due to defects in workmanship &
materials for the life of the original tread, or five years from the date or purchase, (whichever comes first).
A no-charge warranty replacement is available for all other Power King TOWMAX
®
tire lines if a defect
in material or workmanship occurs during the first 2/32nds of an inch of Useable Tread. If you are
entitled to receive a no-charge warranty replacement tire, the mounting & balancing of that tire will
also be provided at no charge

[NevadaNick]

I have ran Maxxis M8008 for years now in E rating and they have been a great tire. I am also in the tow 75mph group. If sizing allows then i would have LT tires. Duro does make a LT in 15in and my buddy next door has been running them with nary a problem at the same speeds i travel. We also travel a lot of gravel roads which is hard on tires.

[Bamaman]

Unless your trailer is capable of handling 16" tires, you may be limited to the Maxxis M8008's in 15" sizes. They should do the job for you.

[Tireman9]

Originally Posted by guy.lawless

I've read a ton of information on this forum and others about LT vs ST tires and would like to know which would be better for my application.

To preface this conversation, I'm not asking for a war between LT or ST tires. I'm also not asking for a debate on traveling faster than 65 MPH.

What I'm asking is this: I've recently purchased a new trailer with Trailer King (possibly a Tow Max re-brand?) tires. The dealer admitted that one had already blown on the way from delivery from the factory and I'm looking to upgrade.

Currently on the trailer are ST225/75R15D tires. While I typically travel around 65 MPH my goal with this is to be able to safely travel with the flow of traffic -- a max of 72 - 75 or so.

As I understand it, I have two options:

• Use LT tires, upgraded to have the same capacity rating.
• Use Load Range E ST tires with an extra 10 PSI.

The drawback with the LT tires, as I understand, is that they are not made to take the lateral force of maneuvering, the load rating isn't as high, and they run hotter.

With the ST tires, I've read that you can safely travel up to 10 MPH over rating (from 65 MPH to 75 MPH) by inflating each tire an extra 10 PSI. In other words, my existing tires are load range D (65 PSI), I'd upgrade to E (80 PSI max) and run them at 75 PSI.

I'm leaning toward the Maxxis ST ST225/75R15E and inflating to 75 PSI but before I do I wanted to ask the question here. I don't necessarily trust the average tire shop to know the ins-and-outs of running each type of tire on a travel trailer.

Thank you all in advance.

As a tire engineer I have to question a few of your statements.

Unless you are running steel body commercial tires I am not sure if ST type tires are all designed with "stiffer" sidewalls. Sidewall stiffness can be achieved in a number of ways but I have not seen any examples of special construction features that would provide increased lateral stiffness.

The increase in the speed rating with an increase in inflation pressure is only in Goodyear Marathons based on a Technical bulletin issued by Goodyear. I don't see how you can apply a GY bulletin to other brand tires. Would you follow a Ford Bulletin if you drove a Chevy?

LT running hotter claim is based on what data? Any tire can be made to run hotter or cooler if you change load and or inflation levels so I am not aware of any sound method of conducting a test that provides an Apples to Apples comparison of operating temperature for different type tires.

Without going into the advisability or need to travel at higher speed I would suggest that you look for a tire that can carry your actual measured tire loading without the need for special exemption of a tech bulletin. AND that you select only from tires that have sidewall speed rating of "L" or better.

[1bigmess]

I can't wait for the folks that know more about how tires are made than you do to come along and tell you that you're wrong.

[Onstar20]

Originally Posted by 1bigmess

I can't wait for the folks that know more about how tires are made than you do to come along and tell you that you're wrong.

https://www.youtube.com/watch?v=r6Sw...ist=WL&index=2

[Tireman9]

Originally Posted by Onstar20

Interesting how he confuses the Max tire seating pressure of 44psi with the inflation that relates to the load capacity. Maybe he just needs to re-read that tire sidewall.

Why did he select a special XL passenger tire rather than a Standard load? XL tires are normally rated for their max load capacity at 41 psi and Standard Load passenger tires are rated for their max load at 35 for American "P" type or 36psi for Euro or "hard" metric type,

This salesman could learn more about tires and Load Range by reading THIS page on tire load from Tire Rack

I do not find a regular passenger tire in either P225/70R16 Xl or Euro-Metric 225/70R16 XL rated for 2,403 so maybe he sells some special non-standard size. Can someone point me to to a P225/70R16 that has a Load Index of 111? Closest I can find is 109 in a hard metric size.

Why is he comparing a Eurometric 225/70R16XL? with a LT225/75R16. Ya they both go on 16" rims but if he is going to ignore fundamental size differences how are we to know about that special chemical that allows faster heat transfer. I never heard about that stuf. Wonder why it isn't used in Indy car tires as they really run hot.

Then he introduces an ST235/80R16 LR-E into the mix and starts to tell us that it is the tire structure that carries the load and not the air pressure.
If its the tire construction that carries the load why did the center of the passenger tire wear more. He claims that faster wear in the center indicates that it is the air that is carrying the load.

IMO This video might be of value for someone that knows nothing about tires and wants some general information but certainly should not be relied on for a fully fact based comparison of tire type.

HERE is a good document with facts about Load and LT type tires along with info on "hard" metric tires.

[tuffr2]

I am following this thread with interest. The OP has picked two good options and 'probably' be ok with either option.

I made my pick. But am always interested in tire constuction advancement but all RV'ers are interested in buying a tire that will not blow out.

I have had two blow outs and neither one was fun.

[Onstar20]

Originally Posted by Tireman9

".....IMO This video might be of value for someone that knows nothing about tires and wants some general information but certainly should not be relied on for a fully fact based comparison of tire type.
....".

Re IMO; Of course, which is more than 90% of those posting only their opinions or what they "heard from the cousin of a friends son" with no facts what-so-ever.

Thanks Tireman9, always look for your substantive content postings.

[tuffr2]

I would add that there are experiences that formula a bases for many of the opinions.

Not just hear say

[1bigmess]

If opinions cause one to drive beyond the safety ratings of vehicle equipment, there is no one to blame, or to pay for the damage, than that vehicle operator, IMO.