Cop wheels have about 2 pounds of extra steel in them. That is the only measureable difference over stock 15X7 wheels.
Trailer wheels should be stiffer and thicker, because trailer wheels do deal with a lot of stress.
You can see how much a regular car wheel can bend when making a tight turn slowly with a trailer (car hauler). I have seen full size hubcaps come flying off of car haulers when taking a turn. I would not recommend ever installing full hubcaps on a trailer with car rims.
I would recommend using the right wheels and tires for the job.
Too many cars, too many parts, too little coin, too little space to work in, too little time left to make it all happen!
Update: down to one ride, still too many parts, a little more jingle in the pocket, gaining space, and it's going to happen this year!
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