I put 19.5" on my Southwind 35P 1997 model, it had 16".
The 19.5 tires far exceed the weight capacity of the 16", a good safety margin.
My speedometer is exactly right according to GPS, it was a little off with the 16" tires.
The height of the 19.5 tires is just a little more than the 16" tires.
I have Sailun S637 Tires on the MH and they are GREAT!!!
Just got back from a trip to Big Bend, TX area and I really like the tires etc. Even helped the fuel mileage a little, due to Lower Roll Resistance...