Mixing Load Range Tires

Thank you.....sorry I don't know how this ended up on 5th wheel forum.

Yeah it can be a very big deal in a hard braking event (braking imbalance) especially on wet pavement. The tire on one end of a axle can have different traction for several reasons ie; different tread pattern......different load ranges (psi)....different tire sizes.....different tire types.
This is the 5th wheel trailer forum so I assume your talking about a trailer although its rare to find a 19.5" tire on a rv trailer.

As long as the steering tires are the same, I don't think a big deal. Only you know how it handles. I don't think you'd notice the difference if used on rear.

Jerry