We added 14" tires
to our 2005 16' Scamp a few years ago. I was prepared to trim fiberglass
from the wheel wells to make them fit, but tried putting them on first and there's enough clearance on ours that I didn't feel a need to trim any fiberglass
Ours has an Al-Ko axle
, not sure if the more prevalent Dexter axles would be the same.
We are on our third set of 14" tires and have had no problems and have traveled from Key West to SW CA to Alaska and Acadia National Park, so have been over many road conditions and many miles.
The main reasons we switched to 14" tires is that the 13" in the D range are hard to find without pre-ordering (hard to do if you need one while traveling), plus the 14" tires have capacities more suited for the 16' Scamp weights when loaded (13" load range C tires are only 1360 lb capacity per tire even though the Scamp GVWR is listed as 3500 lbs).