If you want to upgrade at the logical replacement time :
For trailer usage the best 15 inch tire is a:
Goodyear Cargo G26: size : 225 /70 R 15 C ( commercial )
here is why : 27.4" diameter X 9 " section width
Tire weight is 33 # due to extra cords and rubber .
Made in France or Germany .
rated 2470 # at 65 psi on the 10 % tougher LT scale.
Speed rated 106 mph .
For comparison :
Sharp readers will note that the Goodyear company has to provide a 33 # LT tire to get a 2470 # weight rating .
The Maxxis is rated on the 10 % weaker ST scale and weighs about 90 % of the cargo G26 .
The Maxxis is made in Asia and has less cords and rubber .
The Maxxis is rated for 65 mph .
Consumer Reports has tested passenger care tires and published their results each year in the November issue .
No Maxxis has ever placed above the bottom 25 % of the ratings , ever .