There should be a factory tire size /inflation sticker , close to the drivers seat .
That will give you the size and load rating of the tires you require.
I went to truck tires last year , on my coach , because my home province requires winter tread tires from Oct. 1st , through to March 31st, and I couldn't get traction tires from the makers of MH tires in my size. No issues so far .