205/75/15

For reference:

"C" range tires are 6 ply rated and inflated to 50 psi max

"D" range tires are 8 ply rated and inflated to 65 psi max

"E" range tires are 10 ply rated and inflated to 80 psi max

These are the industry standards but of course there are some bending the accepted rules (mavericks) used to make their tires sound better than their competition. It's called "marketing" and miss-leading marketing claims do NOT make the tire any stronger but so many are sucked in!

I went with Maxxis 205 load range D.

I always do and have gone to a larger than the OEM tire on all our Vehicles, TT's, 5th wheels, boat trailers, etc when replacing the OEM's but only if there's room for a larger tire. Probably well over 2 dozen times so far over the last 40-50 years. The tread depth lasts much longer than OEM's and the tires are not stressed to their max rating. Usually only approx $10 per tire to go bigger and/or stronger and gain so much. It's been a win everytime. The manufacturer never seems to use a heavy/high enough capacity tire to suit me and it's all about cost! What's wrong with having a safety margin anyway as I'm a retired aoutmotive engineer and know better than to design to only 100% of the required minimums. 125%+ makes so much more sense! Just hitting a chuckhole etc with a tire already stressed to 100% can or may be the final tire killer and it's avoidable!

Don't get crazy though with extremes in tire sizes and create other problems like rubbing or hydroplanning during heavy rains. Which vehicle or RV you have can make a lot of difference also and also the climate/weather/temps should be considered on how much larger a tire or type is used.

Those are human lifes being carried in vehicles and even having a blown tire on an RV will ruin a fun vacation or weekend and why? So why not be a little safer and also save money in the long run?

Examples: The 245/75/16 "E" OEM Bridgestone etc tires with 3042 capacity on our trucks were replaced with 265 Michelins with 3415 capacity. The 225/75/15 "D" radials OEM's with 2540 capacity at 65 psi on the trailers were replaced with 225/75/15 "E" range radial tires having 2830 capacity at 80 psi.

Twice I've had to put a 1" spacer between the spring and the axle to gain needed room above the tire but that's no big deal and very cheap to do.

Using the right tool/item for the real task at hand always and then life usually goes so much smoother.

In a GY Marathon the 225 is only 1-1/4" taller. That would only raise the trailer 5/8". A 205/75/15C needs 50psi for a max load of 1820lbs. The 225/75/15C also only needs 50 psi but gives you 2150lbs. On Tirerack the 205 is $86.00. The 225 is $89.00. Seems like a good deal to me.

Only issue is your rim width. 205 needs 5-6.5". 225 needs 6-7". Of yours are 6" then you'd be good to go.

I heard of people putting larger tires on their trailers, but I don't see what advantage that has. If it's a 5er, I can see where that would raise the hitch pin some, giving more clearance for the bed rails of the truck. But on a TT, it will raise your center of gravity slight higher which will affect the towing of the trailer, and everything else you indicated. Unless you are on the road 24x7, more than likely your tires will end up dry-rotting on you (regardless of size) long before they wear tread down. Unless your tires are due for a change, (if it were me), I'd keep what I've got until its time to change, then consider going larger. If your wanting to go larger, just to go larger, think you'll get less wear on a larger tire, like I said, they'll dry rot on you before the tread wears down. So keep what you got. My 2 cents ....

Edit, if it's a wider tire, same diameter, I don't think it will change the overall performance of the tow much. And it will dry rot just the same.

On prior TT, when OE 205's delaminated, I replaced with 225 75R 15 load range E ST Maxxis tires. Ran them 6 years with confidence and zero problems.