"Robin" wrote

I want to replace the tires on my Komet trailer. The original tire
size is P165/80 R13, which is now hard to find.

I plan to tow about 75 mph most of the time. I really want to avoid
sway.

Yes, add another axle behind the one there, then use any tire you want, and
it will never sway again.
--
Jim in NC