Phil, when we bought our coach used from La Mesa RV they told me it had a 40-gallon tank. It was showing nearly empty and when I went to the gas station it took 50 gallons. That pinned the needle on the gauge and I don't think I have ever gotten that much in again only because I never let it get that low. When I called Nexus and asked for the specs from the original sale it showed the 55-gallon tank the original owners opted and I assume, paid for.
Are you saying your E-450 does not have an AC water heater? I thought all of the Ford Class C's came with them. :h When we do have an electric hook up {which is not all that often} I always run ours on AC and save my propane for heat and cooking.
:C
