The manufacture states that my 2018 Sonoma has two 20# LP tanks. Does that mean gallons? On the tanks themselves it says 8.5. I am unsure what these numbers mean. At any rate it wasn't enough for a 4 ...
Please take a lesson about propane. Wikipedia is a great educator. Then Go to your local propane supplier at a bulk station, not at a dispenser, , ask for a lesson in safety, capacity. NFTA 1158 is the go to