Tire size

Changing the rolling radius of the tires and tire weight that much can affect a number of things including the suspension, speedo, engine control computer settings and shift points on the transmission.

Shop around, you'll probably find some on sale or with a rebate to equate the costs.

You are going to take multiple steps backwards... limited CCC, smaller tanks, less combined weight rating, 3K hitch ............... to save a couple hundred dollars a year??????????????????????

PS: some 19.5 tires cost as much as 22.5.

Mostly, I would think. They are also shorter and have less CCC. 22.5 inch tires ride smoother IMHO and have less drag than the smaller tire. Have had both, had much more trouble with the 19.5 inch tires. None with the 22.5. I will be replacing my soon as they are over 5 years old. I am hoping we are still RVing when the next set of tires needs to be replaced, might as well get the most use out of the new ones and not take ANY risk with the old tires.