I don't think the tire is the only issue. Weight capacity is also determined by all the combines suspension parts to include swing arm, etc. It also includes the amount of braking power. I'll give an example. I had a Chevy 1500 1/2 ton pick up with standard cab and bed. I wanted to put a slide in camper on it and did so. But, I first checked out the maximum the truck could handle and what the camper was to way. I bought the camper and went to a truck weigh station to check to see if the rear and front axles were not overloaded. I was max on the rear. So, I took the truck to a shop to add a leaf spring to each side of the rear. I also added tires to match a Chevy 2500 3/4 ton pick up. The company who put the extra leaf springs in said, I now had a 3/4 ton pickup. But what I did not upgrade was the brakes and front suspension parts. With the camper on the truck, everything looked just fine. But my stopping distance at particular speeds had increased, and brakes would get hotter. Point, don't just consider a car tire to solve all the issues. And to let everyone know, I ran a car tire on a Suzuki Burgman 650A that I put an auto style cruise control on. It never wore out but also did not corner quite the same but was safe enough.
Terry Dill of San Antonio
It's not the destination, but the getting there.