Well, our new rig has two 30 lb tanks, so I figure about almost 50 lbs total. Our old rig, a class c had only a single 20 lb tank, and that was good for a week or so as it used gas while on the road for the fridge.
New rig has a 12 volt fridge, so only gas used will be for cooking on stove, for weber grill, and occasionally for water heater (use electric most of the time), so wife asked if this was really needed.
She also did a bit of web surfing and found many use a temperature gun to measure the amount left in the tank. Found they will give an approx amount, not the most accurate, but it will give me an idea that as one tank empties, and second one kicks in, I'll know to get the first filled.
Figure I'll give that a try for awhile as 50 lbs should last us a long time as opposed to our old rig.
US Navy Vet
Retired Law Enforcement
2021 Ford Ranger Lariat
2022 Jayco Jay Feather 24RL