Tired of ST tire blow outs , going to all LT tires

[Fi-Q]

I think upgrading to 16in and lt is the way to go. On my toyhauler rv I just went and put some maxxis E rated ST / 15" because It was a lot more money to go with 6 new aluminium wheels and 6 lt tires plus a new spare. After reading a lot on rv forum, I came to the conclusion that despite going to 16" LT is the best solution, the maxxis where the better 15" option

 

[wolfpack2]

For me it was a simple decision. I talked to a few of the tire engineers that I know and read the tire requirements in the TRA (Tire and Rim Association Inc.) manuals (About TRA). They define the tire requirements that all the manufactures design to for North America which is why all tire of given type (LT, ST, P metric etc.), size and load range all have the same sidewall rating regardless of brand. The construction differences between an LT and ST tires are minimal. The ST may have more UV stabilizer and a slightly harder rubber compound. Beyond that the radial construction is the same. The big difference is they have lower requirements for speed and duty cycle. They only have to meet 65 MPH speed rating at the max load and have only a 80% duty cycle. The LT has a much higher speed rating (95 MPH to 120+) and a 100% duty cycle. This means that the LT tire must be able to carry the rated load 100% of the time at the higher speed whereas the ST only has to carry the rated load for 80% of the test at the lower 65 MPH speed. The ST may also have a higher failure rate before requiring a recall. These are the reasons that a ST tire of the same size and load range as the LT is rated to carry more. It doesn't have to do it as often or as fast which means less heat over the life cycle. Physics would dictate that the same size tire at the same pressure should be able to carry the same load, but the rules change when the duty cycle and test parameters change giving the ST a higher load rating, but no more psychical capability. This is why I have also been changing all of my ST tire to LT tire with the same sidewall max load capability or higher.

 

[Sprinklerman]

That was very well put and informative .

 

[ZAR2USA]

For me it was a simple decision. I talked to a few of the tire engineers that I know and read the tire requirements in the TRA (Tire and Rim Association Inc.) manuals (About TRA). They define the tire requirements that all the manufactures design to for North America which is why all tire of given type (LT, ST, P metric etc.), size and load range all have the same sidewall rating regardless of brand. The construction differences between an LT and ST tires are minimal. The ST may have more UV stabilizer and a slightly harder rubber compound. Beyond that the radial construction is the same. The big difference is they have lower requirements for speed and duty cycle. They only have to meet 65 MPH speed rating at the max load and have only a 80% duty cycle. The LT has a much higher speed rating (95 MPH to 120+) and a 100% duty cycle. This means that the LT tire must be able to carry the rated load 100% of the time at the higher speed whereas the ST only has to carry the rated load for 80% of the test at the lower 65 MPH speed. The ST may also have a higher failure rate before requiring a recall. These are the reasons that a ST tire of the same size and load range as the LT is rated to carry more. It doesn't have to do it as often or as fast which means less heat over the life cycle. Physics would dictate that the same size tire at the same pressure should be able to carry the same load, but the rules change when the duty cycle and test parameters change giving the ST a higher load rating, but no more psychical capability. This is why I have also been changing all of my ST tire to LT tire with the same sidewall max load capability or higher.

Thx for sharing that info. I'm better informed now and going fwd will go with the truck tires on my collection of trailers as I seldom find myself at low speeds and prefer the reliability on long road trips.

 

[bdog]

OP has a good idea. Trailer tires stink. I have a lot of trailers, none are overloaded, and I always have blowouts. I never have blowouts on my trucks even though they see a lot more miles and often they have heavy loads as well.

 

[ksluy]

Last year a group of us headed for Colorado with five campers all 2011 or newer by the time we got there we had six blowouts. These trailer tirs are junk. The only trailer tire I trust is maxxis. I know that Goodyear makes a 10ply 110 p.s.i. trailer tire but its $400 a tire. I was talking to the local tire dealer and i asked him why not just use a E rated truck tire. He said the sidewall construction is stiffer on a trailer tire so there is less sway and the tire will drag better on a tight turn.

 

[wolfpack2]

I keep hearing the tire dealers repeat this line, but on the trailers I have replaced with LT I find the LT to actually be stiffer, track better, and have less sway. I don't believe them. I think it is an old rule based on bias ply tires from 50 years ago, not the modern radial tires. Has anyone every considered this: Why don't the mainstream tire manufacturers (Michelin, Firestone, Cooper, Yokahama, Hankook, Perelli, Continental, etc.) produce ST tires? The only one that does is Good Year, and they have a terrible reputation. Is it because they can't make money at it, or they don't want to damage their reputation due to the lower specifications of the ST tires? Most of these companies produce commercial truck tires and other specialty tires (off road, aircraft, AG, etc.), but not ST tires. Makes you think about why not.

 

[Turbys_1700]

I used to pull a 30' fifth wheel and I have had lots of experience with ST tires...
My rims were 15" on my fifth wheel and 6 lug so I was pretty much stuck with that size...
I ran ST 225 75R 15's...
The best luck I had was with Greenball's...
I always ran max pressures...
I eventually went to E rated tires with a max 80 psi rating...
My rims were only rated to 75 psi so that is what I ran them at...
IMHO ST's do not handle higher tow speeds in higher heat...
Most of the time I was towing my camper was in the summer time and the heat was a factor...
If I was getting another camper it would have 16" rims and I would definitely go with LT E rated tires...
I've blown out plenty of ST's that were in great shape, not old, and properly inflated...
I am not a fan of ST tires...
But I did get a lot of experience in changing them...

 

[tjcarguy]

Tire sales people say lots of stuff like you have to 'buy new tires every 3 years'. ---Trevor

 

[HHR]

I think that lots of people have tried using P rated car tires on trailers with bad results and that is why LT truck tires have been frowned upon. I don't know if they are still made, but Goodyear Wrangler HT 10-ply truck tire works great for trailer use.