LT Tire vs ST Tire
I assumed I wanted ST Tires for my camper and some people are telling me to go with LT Tires. Now I'm confused, and guess I shouldn't assume.
Forum Discussion
D and A plus 6 wrote:
The tire size is 205/75/15 and don't know weight, but it's a Rockwood 8272 S.
I recommend the Maxxis M8008 ST205/75R15-D
http://www.maxxis.com/Industrial/Trailer/M8008-ST-Radial.aspx
Discount tire, America's tire has them.
I just put this on my 7880 GVWR trailer that came with same as your oem size tire.
For LT (more money)
Goodyear Silent Armor LT215/75R15 load range D
http://www.goodyearrvtires.com/tire-selector.aspx- The tire size is 205/75/15 and don't know weight, but it's a Rockwood 8272 S.
Like I said before, it's my father-in-laws and visiting with him today, he thinks he wants to stay with a "ST".
Thanks again for all the input and didn't realize it was such a popular debate. dave54 wrote:
Contrary to the earlier post there is no consensus.
They have stiffer sidewalls, heavier cords
ST's are not necessarily stiffer than LT's. It varies widely from one tire to the next. I've never seen a single ST tire that has a stiffer sidewall than the Michelin XPS Rib or Duramis R250 LT's. After reading the dozens of tire threads on forums I find the vast majority of RV'ers do feel that a good LT makes a better choice over ST's for most applications.
That said if you've had good results with ST's then theres no reason to change. There are a few good manufactures of ST's but they're hard to find. Maxxis and Hercules being two notable decent ST tires. But I've had even better results with XPS Ribs. Less sway, better handling, longer lasting but much more expensive.- I was camping in Hershey Pa about a month ago , ant the guy across from me had a 32 ft 5th wheel . Sunday morning while I was packing up , I heard an explosion . The guys tire exploded while he was set up . I walked over to see what happened , I looked at the other tires on the trailer and he had another tire with tread seperating . they were ST tires with 1 season of use .
Thats why I like LT tires "LT" also stands for Light Trailer - ST tires can be used quite successfully when done right. LT tires can be used successfully when done right. This issue will take you much education to overcome. I have used some ST tires (Maxxis brand) with very good success. There is much passion and misinformation that is disseminated here on this subject routinely. Do a forum search and spend some time reading.
- Every trailering forum on this web needs a sticky at the top of that forum giving instructions to new folks looking for tires for their specific trailers GVWR/axle rating/OEM tire size and load range and/or other info needed for a specific recommendations and other options that the cumulative experience of a forum can give.
Also I would recommend to any new person not familiar with ST tire issues to do a google on the subject. A google has input from all kinds of trailers including RVs. D and A plus 6 wrote:
I assumed I wanted ST Tires for my camper and some people are telling me to go with LT Tires. Now I'm confused, and guess I shouldn't assume.
It's hard to discern what it is you may have wanted from this discussion. You didn't provide tire sizes, your trailer's GAWR information or much of anything that would allow posters to provide you with usable feedback. Then after a few pages of information you say thanks and decide to do some pricing. On what?
There are numerous obstacles that must be surmounted to safely obtain replacement tires that do not match the vehicle's Original Equipment (OE) tires. Suitable clearances for the replacement tires to fit into the trailer's wheelwells. For multi axle trailers, sufficient clearances between the axles must be established for the replacement tire/rim fitments. Rim sizes, load capacities and air pressure requirements for the replacement tires must be adhered to.
Trailers under 10,000# GVWR can be fitted with Passenger tires. It's a consideration often overlooked. Light Truck tires are a popular replacement for Special Trailer tires, so are medium duty truck tires for the heavier trailers.
The key to replacing trailer tires is to follow industry standards for such replacements. It's called "plus sizing". There are numerous references found on the www that list in detail just how those type of replacements are made. I'll list one below. Only use the information that applies to your particular situation.
Bottom line: Read your trailer's owner's manual. Ask your trailer's manufacturer for recommendations. Work with a trusted tire retailer.
Plus Sizing Ref
FastEagleBarneyS wrote:
Francesca Knowles wrote:
Huntindog wrote:
Here is a link to a very good explanation of the govt. testing requirements for each tire type. The actual govt. regs are available, but are difficult and time consuming to research as they keep referring to different sections of the law.
This person did all the work and put this together:
Plain English Testing standards for ST and LT Tires
That so-called "study" gives neither sources nor references of any kind for the information it purports to base its conclusions on. Well, except for nods to other posters here in the Forums. It reads more like a church bulletin than a scientific paper: preaching articles of Faith to The Converted.
Best advice given here came early on: Consult a local tire guy you trust, and buy accordingly."
How do you come to that conclusion when he posted this?
Barney
"The references for my evaluation may be found at the Federal Motor Carrier Safety Administration (FMCSA) webpage:
ST tire standard may be found at FMCSA Part 571, subsection 109.
http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?chunkKey=090163348008f295
LT tire standard may be found at FMCSA Part 571, subsection 139.
http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?chunkkey=090163348008f2a9
Part 571, subsection 139 references Part 571 subsection 119 which can be found at:
http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?chunkKey=090163348008f29d
QUICK NOTES
Each standard for the ST and LT tires has definitions, significant constraints on labeling, etc. that I will not address. There are also tire conditioning (temperature), tire break in, etc. that are the same or similar for ST and LT that I will not address. The details are in the references.
The (3) endurance, and (4) high speed performance tests must not result in tire failure. Tire failure includes visual evidence of tread, sidewall, ply, cord, inner liner, or bead separation, chunking, broken cords, cracking, or open splices, not just a blowout.
TESTING - BEAD UNSEATING RESISTANCE
ST Tire: (reference paragraph S5.2.2)
The tire is mounted horizontally and a vertical load is applied to the tire’s outer sidewall at a rate of 50 mm (2 inches) per minute.
Increase the load until the bead unseats or a specified value is reached.
Repeat the test at least four places equally spaced around the tire circumference.
LT Tire:
Paragraph “S6.6 Tubeless tire bead unseating resistance” references the ST tire procedure noted above.
Conclusion:
The testing for bead unseating resistance is identical for a ST and LT tire.
TESTING - STRENGTH
ST Tire: (reference paragraph S5.3.2.1)
Force a 19 mm (3?4 inch) diameter cylindrical steel plunger with a hemispherical end perpendicularly into the tread rib as near to the centerline as possible, avoiding penetration into the tread groove, at the rate of 50 mm (2 inches) per minute.
Compute the breaking energy for each test point by means of a provided formula.
LT Tire: (reference paragraph S6.5.2)
Each tire shall comply with the requirements of S7.3 of 571.119, which is tires for vehicles weighing 10,000 lb or more. Per S7.3 of 571.119 for our example tire, the testing is the same as the ST tire procedure noted above."
I think this post is well intentioned. However, some tire stores still carry ST tires that don't even have a nylon cap. This is a major disaster waiting to happen. I recommended doing one's own research, and buying a tire from a store that carries whatever brand one is comfortable with.Francesca Knowles wrote:
Huntindog wrote:
Here is a link to a very good explanation of the govt. testing requirements for each tire type. The actual govt. regs are available, but are difficult and time consuming to research as they keep referring to different sections of the law.
This person did all the work and put this together:
Plain English Testing standards for ST and LT Tires
That so-called "study" gives neither sources nor references of any kind for the information it purports to base its conclusions on. Well, except for nods to other posters here in the Forums. It reads more like a church bulletin than a scientific paper: preaching articles of Faith to The Converted.
Best advice given here came early on: Consult a local tire guy you trust, and buy accordingly."
How do you come to that conclusion when he posted this?
Barney
"The references for my evaluation may be found at the Federal Motor Carrier Safety Administration (FMCSA) webpage:
ST tire standard may be found at FMCSA Part 571, subsection 109.
http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?chunkKey=090163348008f295
LT tire standard may be found at FMCSA Part 571, subsection 139.
http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?chunkkey=090163348008f2a9
Part 571, subsection 139 references Part 571 subsection 119 which can be found at:
http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?chunkKey=090163348008f29d
QUICK NOTES
Each standard for the ST and LT tires has definitions, significant constraints on labeling, etc. that I will not address. There are also tire conditioning (temperature), tire break in, etc. that are the same or similar for ST and LT that I will not address. The details are in the references.
The (3) endurance, and (4) high speed performance tests must not result in tire failure. Tire failure includes visual evidence of tread, sidewall, ply, cord, inner liner, or bead separation, chunking, broken cords, cracking, or open splices, not just a blowout.
TESTING - BEAD UNSEATING RESISTANCE
ST Tire: (reference paragraph S5.2.2)
The tire is mounted horizontally and a vertical load is applied to the tire’s outer sidewall at a rate of 50 mm (2 inches) per minute.
Increase the load until the bead unseats or a specified value is reached.
Repeat the test at least four places equally spaced around the tire circumference.
LT Tire:
Paragraph “S6.6 Tubeless tire bead unseating resistance” references the ST tire procedure noted above.
Conclusion:
The testing for bead unseating resistance is identical for a ST and LT tire.
TESTING - STRENGTH
ST Tire: (reference paragraph S5.3.2.1)
Force a 19 mm (3?4 inch) diameter cylindrical steel plunger with a hemispherical end perpendicularly into the tread rib as near to the centerline as possible, avoiding penetration into the tread groove, at the rate of 50 mm (2 inches) per minute.
Compute the breaking energy for each test point by means of a provided formula.
LT Tire: (reference paragraph S6.5.2)
Each tire shall comply with the requirements of S7.3 of 571.119, which is tires for vehicles weighing 10,000 lb or more. Per S7.3 of 571.119 for our example tire, the testing is the same as the ST tire procedure noted above."Francesca Knowles wrote:
Huntindog wrote:
Here is a link to a very good explanation of the govt. testing requirements for each tire type. The actual govt. regs are available, but are difficult and time consuming to research as they keep referring to different sections of the law.
This person did all the work and put this together:
Plain English Testing standards for ST and LT Tires
That so-called "study" gives neither sources nor references of any kind for the information it purports to base its conclusions on. Well, except for nods to other posters here in the Forums. It reads more like a church bulletin than a scientific paper: preaching articles of Faith to The Converted.
Best advice given here came early on: Consult a local tire guy you trust, and buy accordingly.
What was this then?
REFERENCES
The references for my evaluation may be found at the Federal Motor Carrier Safety Administration (FMCSA) webpage:
ST tire standard may be found at FMCSA Part 571, subsection 109.
http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?chunkKey=090163348008f295
LT tire standard may be found at FMCSA Part 571, subsection 139.
http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?chunkkey=090163348008f2a9
Part 571, subsection 139 references Part 571 subsection 119 which can be found at:
http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?chunkKey=090163348008f29d
