Lets talk about the diff between 19.5 and 22.5's on Gassers

Carry more weight

I would think that the 22.5s have a higher weight capacity, but that's ultimately going to be limited by your chassis rating. I would also think that the larger tires would ride significantly better and may wear a little better. As for converting them, there is probably an adapter that would need to be used to attach to the hubs. With that alone, I would NOT want to convert. Anything that needs an adapter becomes a weak point.

If you choose to convert keep in mind you will be changing your applied axle ratio. Tire diameters are figured in as criteria in determining performance values beyond just the tire capacity ratings.

Ready2BRetired wrote:
If you choose to convert keep in mind you will be changing your applied axle ratio. Tire diameters are figured in as criteria in determining performance values beyond just the tire capacity ratings.

Yes, read that BIG change in effective rear axle ratio.

Chassis weight, tire wear
And no, i don't think you can get 22.5 to fit your 19.5 RV
Unless you want to try and lift it up to look like a Monster Truck

Price is significant higher per tire
Just read some of the tire threads taking brands and pricing

Ford has varied a bit over the years, but typically uses the same axle ratio where both a 19.5" and 22.5" wheel is used. But the 19.5" and 22.5" wheels have different bolt patterns, so it's not a simple swap.

Pros: higher weighty rating (but probably not too useful if converting since the rest of the chassis isn't uprated magically), somewhat better ride, perhaps longer life.

Cons: higher cost, heavier weight (which makes it much harder to change a tire in the case of a flat, as well as having some performance penalties that probably don't amount to too much on a motorhome), larger size makes storing a spare rather more difficult.

Many 22.5 setups use a much higher lug not torque than smaller tires and wheels, too, which in turn requires significantly heavier duty tools to manipulate.

Different, but not necessarily pro or con: the diameter is larger, which means a different effective axle ratio, more ground clearance, a higher center of gravity, and possibly interference with the wheel wells or fenders (probably most likely in front).

I would not convert a motorhome I had.

I dont think the chassis engineers design and determine weight limits, gear ratios and wheel sizes by throwing darts at a picture of each.

Cost to gain wasn't in it for me when I looked into it. Hardware along was pushing $1000 per tire (replacement tire and rim) using polished aluminum on four of the six tires. There was an owner on a different forum that posted images of his 30' or so Winnebago class A with 22.5's. A bit odd looking with how high the coach was. Plus the last step off the stairs was a long way down.

Ava wrote:
I dont think the chassis engineers design and determine weight limits, gear ratios and wheel sizes by throwing darts at a picture of each.

It does appear on RV trader that some models are offered in either 19.5 or 22.5 - mainly on the mid-tier products.