We traveled for several years with the original tires
, but as I got further into it I realized that the margin in terms of load was essentially 0. An untenable position in my mind. When I looked for higher rated tire on the 13inch wheels I could not find one.
So I looked at the specs for 14 inchers and found that I could put tires on with significantly higher load limits. Here is what I ended up with:
First of all the wheels: 14" 6.00 JJ 5-bolt, with what I believe is 0 offset
. The originals had 3/4" offset. The tightest clearance was from the tire to the inside, but the 14inchers actually increased
this by 1/4", no problem there. There is, with the new tires, a slightly closer tolerance than original in front of the tire, but not enough so there is a problem. (When brakes
are applied the force would tend to move the wheels backward anyway, so that works well.) No problem anywhere else, including on top.
My trailer is currently at roughly 2850lbs plus 290 tongue weight
. I would guess yours might come in a smidgen higher if you have similar equipment but a roof-top AC. I think my jury-rigged AC comes in quite a bit lighter. It is important to realize that in mine the curb side is about 200+ lbs lighter than the street side because of all the appliances and kitchen. This is apparently not unusual, but it means that the instantaneous load on the street tire during a high-speed right turn could be much higher.
I went to Les Schwab and we discussed the clearances in order to get the right combination of wheels and tires. (They were very helpful). The wheels are the standard-looking trailer wheels, white with pinstripes, etc. The tires are a brand I never heard of, and they had to order them. From the code I believe they were made in a factory in Israel (!). Look like good tires to me, and I'm well satisfied. Here is what the markings are:
"Super Trac, ST2000"
DOT 1NL7 F78-14
6 P.R. Load range C
Max load 1760 lbs @ 50 psi
ST205/75 C 14/6 AWC 729 Hi Speed Trailer
(cost me 47.63 per tire, mounted and balanced).
With the load as it is, the formula they gave me ended up with a suggested pressure of about 45psi. I sometimes run them a bit closer to 50psi, but the difference is trivial. The old 13inchers ran at 60 or 65psi, I believe, and considerably rougher.
There are some other benefits in that there is slightly
more road clearance, which also affects ease of dumping and the like.
Good luck changing these out. When I saw the numbers the changeover was a no-brainer.