Welcome to the forum and congrats on your purchase!
I can be a little more helpful.
I have attached the brochure for your that I pulled down from Thor's website. According to the brochure, there is only a single house battery. There is no Inverter listed but it does come with a 100W solar panel and solar controller.
Can't help with fuel economy but with gas so cheap right now, don't worry too much about it and get out and enjoy it!
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