Tires; revisited; yet again

hammer21661 wrote:
st tires are only rated at 65 mph. Do I need to say more?

yes, based on actual load and load rating.

from goodyear

Thank you for contacting our web site. You don't "derate" an LT tire when
using on a trailer application. You do "derate" a Pmetric tire if you use
it on a trailer or on a truck. Reason is an LT tire is designed to operate
at max load 100% of it's life. A Pmetric is designed to operate at max
load only part of its life. Rule of thumb is to "derate" a Pmetric in this
type of application by 10%.

If you've had good luck with the Marathons on your trailer, I would
continue to use them.

Jennifer - Consumer Relations





Inflation

Always inflate trailer tires to the maximum inflation indicated on the sidewall.
Check inflation when the tires are cool and have not been exposed to the sun.
If the tires are hot to the touch from operation, add three psi to the max inflation.
Underinflation is the number one cause of trailer tire failure.

Load Carrying Capacity

All tires must be identical in size for the tires to properly manage the weight of the trailer.
The combined capacity of the tires must equal or exceed the Gross Vehicle Weight (GVW) of the axle.
The combined capacity of all of the tires should exceed the loaded trailer weight by 20 percent.
If the actual weight is not available, use the trailer GVW. If a tire fails on a tandem axle trailer, you should replace both tires on that side. The remaining tire is likely to have been subjected to excessive loading.
If the tires are replaced with tires of larger diameter, the tongue height may need to be adjusted to maintain proper weight distribution.

Time

Time and the elements weaken a trailer tire.
In approximately three years, roughly one-third of the tire's strength is gone.
Three to five years is the projected life of a normal trailer tire.
It is suggested that trailer tires be replaced after three to four years of service regardless of tread depth or tire appearance.

Mileage

Trailer tires are not designed to wear out.
The life of a trailer tire is limited by time and duty cycles.
The mileage expectation of a trailer tire is 5,000 to 12,000 miles.

Why Use An "ST" Tire

"ST" tires feature materials and construction to meet the higher load requirements and demands of trailering.
The polyester cords are bigger than they would be for a comparable "P" or "LT" tire.
The steel cords have a larger diameter and greater tensile strength to meet the additional load requirements.
"ST" tire rubber compounds contain more chemicals to resist weather and ozone cracking.