Well, he said he wasnt sure, but he figured 16-18 gallons. I did do some research on ebay, and I couldnt find the right one that corresponded with your panel, but it was something around 20 gallons. So, I think its at least 20 gallons, if the manual says so, then its true as long as its the correct one, and thats the original gas tank. Thought I would try to help, thanks!
- Shane
