Why do the hubcaps or rims on trucks always have the front one sticking out and the back ones going in?

Question

I see this on a lot of trucks, the wheels are designed to look like they poke out on the front, but in the back, it always looks like it's pushed in.

Answer 1

On the back they have to put 2 tires together to handle the  weight that is going to be carried on top of them. At the same time both tires have to be bolted together with the same bolts. And that is the only way that they can do it.

On the front IF they put the tire on the other way it would stick way out of the side of the truck and interfere with other vehicles driving by.

Answer 2

Because the rear tires are double, they mount opposite each other. Hence , the outer rim mounts with the concave side facing out.