Not sure what you’re getting at here. As the terms are essentially interchangeable. Albeit one has to understand the difference in the two terms. (Which you do, of course) 0 offset on a 6” wide wheel will put the tire in the same spot as 0 offset on a 12” wide wheel. However that’s a big generalization to say 4” BS is what’s needed because that’s a completely different setup if it’s a 6” rim with 4” bs vs a 12” rim with 4” bs.
IMO it’s just 2 different ways of saying the same thing but like I said earlier there’s 3 or I suppose 4 factors when determining fit. Tire height, tire width, rim width and “backspacing.”
Of course I just noticed I used the words rim and wheel interchangeably as well. Which also could be debated. Lol
My only point was that the term "offset" is just a waste of time when searching for wheels. Backspacing is what is important. Let's just say OP is looking at all sorts of wheels, 16x7 through 17x11. The amount of allowable backspacing is a set distance, you can only go so far. So if searching through all the various wheels available, do you want to do math for each wheel to figure out which offset may or may not fit, or do you just want to look at the backspacing spec?
As I said earlier, 4" +/- 1/4" is a pretty safe bet when giving advice on the internet. You can get away with a little bit more, depending on 1/2 ton, 3/4 ton, 1 ton, wheel diameter and composition. So if someone really wants to stuff as much wheel and tire as they can under their truck, they need to get out and use a tape measure to see how much backspacing they can get away with.
Yes, backspacing and offset are basically the same thing. But, one requires math to know if it fits your needs and the other one does not.
Oh, and even the factory narrow (15x6, 16x6.5 and 16.5x6.75) steel wheels have around 3.75" backspacing or so.
