I full time with a 5th wheeler and have all Mobile 1 Delvac dropped shipped 4 gallons at a time from
http://store.avlube.com/fonfacsizcol.html
to where ever we are going to be in about a week. Last shipment was about $83 with UPS charges. If you can find at a truck stop it will run about $30/gal.
I have 7K on the current oil change and the stuff is still clean. The computer says I have 40% engine oil life remaining. And I do a LOT of towing.
Pretty good stuff...
2003 K3500 Crew Cab, Banks Stinger Pkg, Exhaust Brake & Exhaust, OilGuard Bypass filter, Lube Specialist Secondary Fuel Filter, Allison Deep Pan, TTT Mirrors, B&W Turnover Ball and Companion Hitch, Truck Trunk Sliding Box and V-Box, LINE-X, Co-Pilot Live GPS, Hitchhiker 31.5 LKTG 5th Wheel 28' Wells-Cargo Gooseneck Car Hauler