SAM's Club and Tire Rack websites provide a lot of good info.
The best E rated 16" tire available for trailers is the Michelin XPS Rib trailer tire in size LT235/80 R16 LRE. They are an all steel casing, very heavy, and very strong.
If your friend has 16" wheels on his trailer, XPS Ribs will cure his tire problems. The Michelins are not cheap though. Current prices are around $225/tire.
If he has 15" wheels and tires, I would recommend changing to 16" wheels and tires.
Asked him about the Michelin XPS rib he said no longer made.
Just got back from COSTCO stoped by the tire shop to say hi to the Guy that always puts me at the front of the line. Asked him about the Michelin XPS rib he said no longer made. So my son went with the Bridgestone commercial TA the same tire I have so far I like them only have about 5000 miles on them but the wear is good and hold air like no other tire I have ever had. Diffrent size than above post
Gail,
Didn't you mean BF Goodrich Commercial T/A not Bridgestone?
The BFG is the next best thing to Michelins, IMO.