Proper carrying of propane tanks

Try Century Fuel Products, good folks. 

When we traveled in the winter, I was having to fill a tank every two or three days because it was so cold out. I do carry a spare now in the bed of the truck. Changing to a dual-mount means that I can have the auto-switchover which means that I won't run out in the middle of the night and have to run out and change it if we were to do cold weather camping again. Otherwise, it is purely for convenience as I can better utilize the tongue space to carry the dual tanks plus a 5 gallon gas container outside. I had one gasoline container leak and it ruined part of the truck bed lining which did not make me happy at all. It was one of those gas cans that had the spout attached at the bottom that swiveled down and then a push button was used to activate the spout to dispense the gasoline. It worked well for filling the generator, but the pressure vapor pressure generated when it was closed and the temperature went up overcame the seal, causing the leak. Unfortunately, it was outside the warranty period. I definitely gave that product a one (only because I couldn't give it a zero) star review!

Its perfectly legal to transport propane cylinders in an enclosed vehicle. You just can't carry more than 90 lbs propane inside, and the cylinders can't be bigger than 45 lbs.  The cylinders have to be secured properly on a flat surface, regardless of whether you carry them in an open truck or inside. If the cylinders are in an open truck and less than 45 lbs they can be on their side, in an enclosed vehicle they have to be upright unless smaller than 4.2 lbs. This is per NFPA 58 for transport of propane (as opposed to mounting propane tanks in or on an RV). 

Originally posted by offgrid StephenH can afford to add more propane because he removed his lead acid batteries from the tongue, and if I was planning a trip to Alaska I'd want to carry plenty of propane too.  But for the rest of us, yes, your question is not dumb at all.  I wouldn't want a 30 lb tank personally because that would eliminate the option of swapping tanks out at a convenience store. The other solution is just to carry an additional 20lb tank in your tow vehicle.