Gas consumption

It's bit like how long is a piece of string.
Gas usage is subject to, how long in shower and other usage of the HWS. plus how many times the fridge is opened when running on gas and the ambient temp it is working in.
Your best bet is to have an auxiliary gas bottle then run the system on gas for a trial trip and see how long i really lasts.

We have twin 4.5 bottles on our rig an with showering every 2nd day (to conserve water) plus the hot water service turned off during the night plus the fridge is left running on gas we can get 10days out of each bottle. (fridge 90ltr) when the ambient temp is around 25+% cels. This for 2 people only and 3 minute showers.

we have 2 x 9kg bottles on our van. If I know it's pretty full I just take the one bottle. (we don't do big trips beyond 3 wks with school age kids) If you think there's any danger of running out of gas, just take a spare with some in to give you time to refill the other. We don't time our showers now, but heat the water up, wet yourself turn it off and scrub. Then turn on again and rinse. Usually takes about 8L of water without getting fanatical about it. We only heat the water up once and all 4 of us shower and then turn off. Usually have a bit of hot left for washing up but also use the campfire and the billy's always on for brews and washing. Never checked tbh but ia bottle lasts ok. Like the previous post said, always have a spare handy, even if it's not full. 3 min showers are pretty good going. I reckon you get a decent wash but you've gotta get a move on. If you do a search on here you'll find some manage with a teaspoonful but you've gotta be quick

;)))

Do you know what the megajoule per hour rate [mj/hr] is for the appliance found on the AGA appliance approval plate ,AS thiS will assist in the equation/answer to the question
Russ