Soo.. my car sits in the garage A LOT... I tend to go about a 4 weeks to 6 weeks before needing to fill up the SHO.. do I need to be worried about E20 sitting too long in the lines?
4 to 6 weeks should not be an issue, assuming the car is regularly driven. If it does sit around, add a product like STABIL, or HEET, or Ethanol Drier to every, or every other, tankful.
With sitting for 4 weeks I would use stabilize in every gas tank because gas will also start to create a wax surface to the lines and tank I'm not sure if the detergents in gas reverse this.
For one year I let my Subaru sit many months before needing a new tank due to my job and having my wife's car parked behind my car so easier to take hers.
Still haven't seemed to have issues from that except for the charcoal tank seemed to go bad and have issues filling up the take in winter but sometimes in summer issue goes away.
Wife wasn't driving the sho when I left to work so I started using stabilize in the tank when I left. This time she's been driving it so probably not going to do it anymore.