When i bought my 94 MicroWarrior it had two tanks, the standard and an additional one which I think may also be 17 gals. The secondary feeds the generator. It's been really convenient, especially after having experienced an older '83 22' Lazy Daze which drank fuel like a beast and was built like a tank. I miss the sturdiness of that RV though and wish Lazy Daze would venture into shorter lengths again.