My car sat, not being fired up for 4 years before I got it. It had 1/2 tank of standard 2013 So Cal pump gas in it. No treatments of any kind. I got it home and sprayed a little starter fluid (I know I know) and it fired up. I expected it to die after the starter fluid was used up but it kept running. I filled the tank full and ran it to near empty, filled again and never looked back. I think the conditions the fuel is stored in makes the biggest difference. The car was stored in my mom's garage in So Cal, a few miles from the ocean. It can get a bit humid there but nothing like the eastern part of the country.
