Storing with gas in tank, for a year or more?

[Naio]

Hi folks, I'd like your advice!

I probably won't be driving my van in the next 12 months.

It has a full gas tank, regular gas. It's up on leveling blocks and I would like to keep it that way, because it was level when it was loaded for travel and I have since unloaded it. I want to build some cabinets in there and I want to maintain my sense of what is level when loaded.

I have some startron, and possibly also some seafoam. I didn't add anything when I filled the tank. If I add some now, and leave the engine running for half an hour or so, will that mix the startron in well enough? Or is it going to eat a hole in my gas fill tube or something?

[2oldman]

My research shows startron is not for keeping fuel viable. Stabil is, but 'up to a year.'

I regularly leave fuel in my car over the winter for 6 months sans anything, and it's fine. Gas without any additive is good for 6 months.