Just acquired a 2003 Mazda B4000 4x4 cab Plus. Manufactured by Ford in the U.S. This truck with 17in tires. It seems to work fine. Is this the right size for off road and on road use?

 

Welcome to the forum

I think you mean 17" Wheels/Rims

For off road most prefer a wider side wall to absorb bumps, more than 6"
For on road most prefer a narrower side wall for less roll when cornering, less that 4"

Tires come with a diameter, lets say 30" tire
30(tire) - 17(wheel) = 13" divided by 2 = 6.5" side wall
30(tire) - 15(wheel) = 15" divided by 2 = 7.5" side wall

So not much of a difference, only 1", and above 4" so still not great for cornering, lol