I run 3500 miles on the oil in my 35' motorhome(Ford V10) so I'm running a mix of oil that I have at home(till its gone).
4 qts of T5 10/30, 2 qts of Mobil 1 0/20 AFE and 1 qt of Mobil 1 Turbo Diesel Truck 5/40.
I got enough oil for three oil changes with this mix then I'll go with Mobil 1 5/30.
I also found that getting oil into the motorhome was a lot harder than any car or truck I've ever had. So I went to Home Depot and got a 2 gal. sprayer. I took the stock sprayer hose off and put a larger and longer hose on it with a on/off petcock. Now all I do is put the oil in the sprayer, pump it up, put the hose in the oil filler and turn on the petcock till all the oil is gone.
ROD