Trailer Tires
5500 GVWR travel trailer needs 4 Tires (7 years old). OEM Spec - ST205/75R15C

I've always had GY Marathons on my trailers without issue but like others have heard stories. I'm considering the GY Endurance ST205/75R15D N (87 mph) as a replacement.

If I upgrade to D Tires should I continue to run 50 psi (Wheels will allow 65 psi). That's 8600 lb worth of tires which is double what is typically the axle weight of that trailer.

 

https://www.goodyearrvtires.com/pdfs/rv_inflation.pdf

 

The trailer manufacturer recommended running at the 50 psi rating pressure on ST-C. I would be hesitant to reduce the pressure below that. I'm assuming it was for sway prevention since technically the tires have a 50% Reserve Capacity at that level and would technically support the GAWR at 26 psi.

 

Those Goodyear Endurance tires are nice... I have a pair on my boat trailer.

 

What about the spare?
I've only owned my current travel trailer going into its third summer.
On my Cargo and boat trailers I had I ran the tires till a problem occurred.
The couple RV forums I belong to are pretty adamant about trailer tires aging out before wearing out and five years from build date (stamped on the tire) is the age where problems start. Some have discussed problems occurring on a never used covered spare suspected due to age.
Also, apparently trailer tires don't usually get balanced unless you tell them to do it.

 

I was planning to change the spare too. Just didn't think to include it in the count. I'm not a stickler about 5 year age out if the tires have some reserve (I'm at 7280 lb with my normal load at around 4300 GAW) hence the 7 years . If I was running close to max on the tires I would be much more of a stickler.

Technically if protected from UV and never subjected to heating cycles the spare should age out more slowly than the service tires. That said the spare is 7 years old as well so I'm replacing it.

 

I also have heard nothing but good reviews about the endurance. They will be my next tire as well, I'm only at 5 years right now.

 

The 15" tires are getting a little hard to find in ST tires.

But the best two ST tires are the Goodyear Endurance and the Maxxis M8008's.

All the rest of the ST tires on the retail market are just Chinese junk--and that includes Goodyear Marathons. Avoid them like the plague.

The exception to Chinese tires is the Sailun brand of tires--sold thru Walmart. They make a G rated tire that's put on big full size RV's and I've never heard a complaint. I put two Sailuns on the front of my F250 last week at half the cost of the Michelins on the rear.

 

I use tires like the Michelin Rib, except they a Bridgstone version. I had way too many blowouts with S/T tires as they have a low speed rating. Seems the heat of TX
and the 70-mph towing would wipe them out. If I were driving the Alcan I would run a LT tire at max pressure, and carry an extra. Lots of places there where you are
a long ways from any place that would have service.

I also swapped out the RV axels with the non-serviceable bearings for standard 7000-lb axels I could lube.

 

You put the max which is on the sidewall, which is 65psi. 50psi is underinflated for that tire. I have them also and asked the same question. I did more research and found 65psi. I don't run more than 65mph.