To see any savings, you need to use your casings and the value of a 16" tire casing is ?. Once you get in the commercial size, 19. 5 and up there is some value in the casing. UPS uses them on the rear of their vehicles.
When I was running log trucks, we used them a-lot. However it was mostly off highway. They save money if ya don't buy casing and all. There always seemed to be some waste tho, you have to watch your tires real close and pull them off with some tread left or when they buff the tread off there will be unseen damage and they will cull the case. Sometimes it would pay to just put them on the trailers (when the tread was low) and run them till there was nothing left.
"NICK"