Perhaps some of you replying here to the post should actually get out got the track and ask the manufacturers what they suggest for these tires in these types of applications. I do and have I also race one of these cars. The same class as the video is from. We all run 12" wheels as suggested we do from the manufacturer of the tire M/T for a 29.5x10.5 tire. On the outlaw 8.5 tire we use a 10"'wide rim as suggested by the tire techs from M/T.

The reasoning behind why we do has been pointed out here already. We get a bigger footprint and can run more air in the tires. But you can just read them catalogs and use those conservative recommendations. For those of us trying to truly maximize our programs we will continue to work with all the manufacturers to get the most we can from our cars.