Here the info on Propane usage someone requested a few days ago;

I hope this answers your question on how long the propane tank will run the
Westy Dometic fridge.

        Propane Gas produces the following;
        -----------------------------------
        1 pound of propane produces 21591 BTU's
        1 gallon of propane produces 91690 BTU's
        3 gallons of propane produces 275070 BTU's  (Westy tank is 3 gallons)

        Dometic fridge uses 650 BTU's per hour on high (max)

        soooooooo...

        275070 BTU's in a 3 gallon tank / 650 BTU's per hour used for fridge

        = 423 hours (or 17.5 days)

Richard - 85 Westy 118K