Tire Pressure/ Speed

[Daveak]

Reading information here and other places about tire pressure and max speeds of 65mph. I am fine with going no more than 65. What about my tire pressure? If there is a sticker on my trailer, I cannot find it. I can fill to the max pressure of my tires (50-55 psi) and go with that, but are there any over-inflation issues? I cannot remember much about my tires right now... but they are load range C tires. Is that a standard trailer tire?

There is no note on the tires or anywhere else I remember about not exceeding 65mph, where would I find that? Thank you.

[mcfarmall]

Maximum inflation pressure is molded into the sidewall of the tire.

See your tire manufacturers website for proof of maximum speed limit.

Most trailer tire size nomenclature will look something like this: ST185/80R13.
SpecialTrailer
185 mm tread width
80 sidewall/tread ratio
R radial
13 wheel (rim) diameter

[Bob Landry]

It may not be stamped on the tire, but all ST tires are rated at 65 MPH. Your manual will probably say that somewhere.

[eldermike]

Load range is based on number of plys in the tire and at maximun pressure listed on the tire. Lower than max pressure derates the tires load range.
The sticker is yellow and it should be on the driver side close to the front of the TT. It will agree with the max pressure listed on the tires.

It's very important to:
1) Set the tire pressure when the tires are cold at the max listed on the sticker/ tires.
2) Check you lug nuts.
3) Keep your ST tires no longer than 4 years from date of manufacturer of tire (it's on the tire) Tires derate with time. Ozone and UV are the reasons, you can fix one of these but not the other one so there is actually no need to fix one because the other one is equal in degrading tires.

[clutch]

I always run trailer tires at the maximum PSI listed on the tire. Chances are the owners manual will refer to the tire sidewall.

[DocBrown]

Your owners manual will tell you the correct PSI. However, I've owned 3 Jaycos that we bought new and every one of them said to use the max PSI stamped on the sidewall. 50 psi on the current trailer and previous one.

Everything you wanted to know about ST tires

[Shorty Cox]

This is info I received from Goodyear regarding "speed and pressure"



Special Trailer (“ST”) Tires
Goodyear Marathon trailer tires are widely used in a variety of towable
trailer applications and are designed and branded as “ST” (Special Trailer)
tires.
• Goodyear Marathon Special Trailer tires, with the “ST” size designation,
are speed rated at 65 MPH (105 km/h) under normal inflation and load
conditions.
• This speed rating is based on Tire and Rim Association loads and
inflation pressures for ST trailer tires without a service description for
speeds up through 65 mph. (ref: TRA 2013 Year Book)
• If Goodyear tires, with the ST designation, are used at speeds between 66
and 75 mph (106 km/h and 120 km/h), we recommend the cold inflation
pressure be increased by 10 psi (70 kPa) above the recommended pressure
based on the trailer placard for normal inflation and load conditions. You
should also consult your trailer manufacturer’s Owner’s Manual for maximum
operating speed recommendations for the trailer.

o Increasing the inflation pressure by 10 psi (70 kPa) does not provide any
additional load carrying capacity.
o Do not exceed the maximum pressure for the wheel or the valve.
o If the maximum pressure for the wheel or valve prohibits the increase of
inflation pressure, then the 65 mph rated speed must observed as the
maximum speed.
o It may be necessary to dismount the tire from the wheel to determine the
maximum rated inflation for the wheel and valve. *

*Details about wheel and valve inspection:
a) If the rated (maximum allowable) inflation pressure is not visible on
the wheel, consult the wheel or trailer manufacturer.
b) Tubeless snap-in type valves, depending on the type valve, are rated for
a maximum inflation pressure of 65 or 80 psi for nominal 0.453” diameter
valve holes. If a higher cold inflation pressure is used, a clamp-in valve
such as TR416S valve (200 psi maximum inflation) must be installed.

Important trailer tire care information and load / inflation tables are
available on Goodyear’s Recreational Vehicle web site at
www.goodyear.com/rv. Encourage your trailer tire customers to use this
information.
• Drivers should always obey posted speed limits and reduce speeds when
necessary based on vehicle, road, weather, or traffic conditions.

• Light Truck (“LT”) designated tires do not have the same load carrying
capacity as ST tires. If LT tires are used on trailer applications, the
inflation pressure and/or tire sizing will need to be adjusted to match the
load carrying requirements of the trailer.

• Cold inflation pressures should be checked every morning during trips and
monthly while in storage.

• Vehicles or trailers should not be overloaded. The tire information
placard, vehicle certification labels, and/or owner’s manual should be
checked for the maximum Gross Vehicle Weight Rating (GVWR) and the fully
loaded trailer must not exceed that weight.

• Vehicle speed, load and inflation pressures, all of which are within
control of the driver, are critical factors for the safe and enjoyable
operation of any vehicle.

Jennifer - Consumer Relations