I think you would be better measuring up your rims as my 14 with 15"rims while 6 stud I could fit Nissan rims to it, can't recall what offset but it wasn't the same as the OE rims but I just measured from the chassis rail to the outer edge of the hub, subtracted 25mm from it and that gave me a size that would fit without hitting anything. Measured the rim from inside to edge of rim.
Have a look here, it will show you the way to measure offset. I took a wheel off, laid it flat on the ground and measured from ground to the face it mounts to then turned it over and measured the same again. Half the difference was the offset, just be aware of whether it is +ve or -ve. It happened that my Journey wheel was 0 offset.
Hello Hamish, how did you go with the -10 offset?
I have been trying to find out the Jayco standard offset.
The wheels I would like to use are, Dynamic Sunraysia 16” X 7” 6 stud with 0 or -11 off set, with 245 / 70 R16 All Terrain.