Thank you your responses, all! It seems that everyone has a different experience with tires.
I have to admit that I am taken aback by the potential cost of having to replace my travel trailer tires every 3-4 years when my truck tires (and brakes) lasted 7 years.
I have also been told by tire sales reps that ST tires have firmer sidewalls, and I have also read that as Jim says, the firmer sidewalls in a higher-ply make for a much less bouncy ride, which is important to me, but then what Tom says about the specs for the Kuhmo Radial 857 in size 205R14C makes a lot of sense and this is the 2nd time someone in the FGRV community has recommended that particular tire (thanks, both of you).
Thanks, Roger, Norm and Ginny on the reminder about the importance of proper inflation and speed!
Thanks, Mike, for explaining the rationale for upping the tire size. Even though I would not expect to exceed 60-65 mph maximum ever when towing, I would definitely want the higher speed rating that you mention. I really do not want to experience a blow out if I can avoid it.
Luckily or not, I have some other exterior work on the TT to do myself first and then some other budget priorities, so will probably be waiting until summer's end to get new tires and then have my trusty mechanic install new brakes
, bearings and shocks at the same time.
Meanwhile, I will have some more time to research what travel trailer users say about the Kumho Radial 857 205R14C versus the Maxxis ST M8008 (which I think are available in the 14" on some sites). Reading the forums, it sounds like there are some important distinctions between using tires on 5th wheels, RVs and travel trailers in terms of how the bulk of the weight
is distributed at rest and in motion (RVs being more similar to trucks because of their front axle
performing steering functions, while 5th wheels and travel trailers just follow the steering from the tow vehicle). Sometimes I find that there is more online than I really want to know, but I would rather be over-informed than under-informed... as long as I can finally find something that is reliable and fits my budget!