The other day my Vet came by and while driving down to the pasture ran over something that punctured the side wall of the tire. It punched through near the tread only a couple of inches from the ground up on the side wall. I think it was a limb or old rotted stump he rolled over and rolled over caught on the sidewall. He did not have a spare with him and only had to drive a little ways and on back roads to get to the office and onward home. So, I plugged it with a basic tire plug to get him home. I know tires are steel belted for reinforcement and have layers and/or ply's. The tread part usually has at least a few more layers than the side wall. So did I do a no-no and plug a sidewall that is weaker than the tread and significantly increased likely hood of a blow out? I told him I did not know if it was ok to do it and be careful not to drive on interstate in case it blew out. It was a Dodge 2500 5.9 Cummins with D rated tires mastercraft brand tires and he always has about 2500 lbs in the bed of his truck (Vet supplies) in a big heavy duty organizer/toolbox thingy.