The registration sticker on the side of our trailer shows a 15" spec 6 lug setup as standard, yet the trailer came with 16 inch 235s.
Can it be done? more than likely. The big thing is making sure there is enough distance between the two tires. Mine are around 2 inches apart and I can barely get my scissor chock in there.
Also there will be a noticable height difference which means you may have to re-level your trailer.
Also, the tire size is less critical than the weight rating. In other words don't go by size, go by load rating of the tire. C, D, E ect.
1999 Ford Superduty F250 PSD CC SB 6spd 4x4.
B&W goosneck/companion hitch, Airlift 5000 airbags.
2006 Sierra F28 Rear Kitchen 5th Wheel, 31' = 10k pounds.
Nights camped in 09-14, 2010-23