Jayco RV Owners Forum

Thread Tools Display Modes
Old 04-09-2014, 06:12 AM   #1
Senior Member
Join Date: Jul 2010
Location: Oklahoma panhandle
Posts: 328
And the debate goes on!

I'm sure many of you also monitor other RV forums and or frequent them. I find it interesting that on all of forums, there are several threads regarding ST vs LT tires. I have concluded; No one knows which is actually best to use. It is like which is best, FORD or CHEVY. We all know the correct answer, but I can't, and never will, convence you that I'm right.

Just my observation, And the debate goes on!!!


Shorty Cox is offline   Reply With Quote
Old 04-09-2014, 07:03 AM   #2
Senior Member
Join Date: May 2013
Location: SE Wisconsin
Posts: 1,802
The trouble is that what works for some doesn't work for others. One big factor in this is how people drive. There are those that drive 70 mph+. Can't do that with most STs and expect them to be reliable.

2013 Jayco Jayfeather X20 E, 2008 GMC Sierra 1500 Crew Cab Z71 SLE
DocBrown is offline   Reply With Quote
Old 04-09-2014, 09:15 AM   #3
Senior Member
Scott's Avatar
Join Date: May 2013
Location: Grayslake, IL
Posts: 292
I have heard the ST tires have a special additive because they sit so much and LT tires don't. This additive makes ST tires last longer than an LT tire given these conditions. Any truth to that?
Scott, DW, and Twin DS (5)

2013 Jayco Jay 1206
2005 Chevy Trailblazer
Scott is offline   Reply With Quote
Old 04-09-2014, 07:18 PM   #4
Senior Member
3'senough's Avatar
Join Date: Sep 2010
Location: New York
Posts: 1,862
Here is an interesting web posting on tire rack that describes some specifics on the ST LT debate as well as some interesting info on Power King Towmax and Marathons that I was not aware of.

Purely passing this on and not making a case either way, but it does make one think...

"There are differences in the driving requirements between the tires on your trailer and those on the car or light truck you used to tow it. Therefore there are distinct differences between the way trailer tires and tow vehicle tires are engineered.

Your tow vehicle is a leader, which means traction is a key focus in the design of its tires. Traction allows your tow vehicle to accelerate down the road, turn around the corner and brake to a stop. Another important consideration is tow vehicle tires are designed for ride comfort, which is achieved in part by allowing their sidewalls to flex.

Your trailer is a follower, which often makes tire sidewall flexing a negative. Sidewall flexing on trailers, especially those with a high center of gravity (enclosed/travel trailers) or that carry heavy loads, is a primary cause of trailer sway. Typical passenger radial tires with flexible sidewalls can accentuate trailer sway problems. The stiffer sidewalls and higher operating pressures common with Special Trailer (ST) designated tires help reduce trailer sway.

Also consider that Special Trailer (ST), as well as Light Truck (LT) tires are fully rated for trailer applications. This means ST- and LT-sized tires can carry the full weight rating branded on the sidewalls when used on a trailer.

However when P-metric or Euro-metric tires are used on a trailer, the load capacity branded on the sidewalls must be reduced by 9%. This means P-metric or Euro-metric tires with a maximum branded load rating of 1,874 lbs. for use on a car is only rated to carry 1,705 lbs. when used on a trailer.

Comparing the load capacities of a pair of tires of the same dimensions fitted to a single axle trailer, ST225/75R15 Load Range C-sized tires inflated to their maximum of 50 psi provide 4,300 lbs. of load capacity, where P225/75R15 Standard Load-sized tires inflated to their maximum of 35 psi would be limited to 3,410 lbs. of load capacity, a total reduction of 890 pounds.

Trailers will be more stable and pull better on tires designed specifically for trailer use. Since Special Trailer (ST) tires are constructed with heavier duty materials, they are tougher than typical passenger vehicle tires. This is a plus because trailer suspension systems are generally stiffer and less sophisticated than automotive suspension systems.

Special Trailer (ST) Tire Speed Ratings

Industry standards dictate tires with the ST designation are speed rated to 65 MPH (104 km/h) under normal inflation and load conditions.

However Goodyear Marathon and Power King Towmax STR tires featuring the ST size designation may be used at speeds between 66 and 75 mph (106 and 121 km/h) by increasing their cold inflation pressure by 10 psi (69 kPa) above the recommended pressure for the rated maximum load.

Do not exceed the wheel’s maximum rated pressure. If the maximum pressure for the wheel prohibits the increase of air pressure, then maximum speed must be restricted to 65 mph (104 km/h).

The cold inflation pressure must not exceed 10 psi (69 kPa) beyond the inflation specified for the maximum load of the tire.

Increasing the inflation pressure by 10 psi (69 kPa) does not provide any additional load carrying capacity."

2014 375 BHFS Eagle Premier
2014 Ram 3500 Longhorn DRW CC
6.7 CTD, Aisin, 4.10's
Yamaha EF3000iSEB
3'senough is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

» Virginia State Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -6. The time now is 02:16 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.