So today I changed out my fuel filter. This one is a "stock" replacement from autozone. I installed this in nov 2009. It has about 2500miles on it of straight E85. Never once ran gasoline through this filter. I cut it apart to see if the paper has broken down and apart like has been said will happen. This is what i found.
Nothing wrong with this filter. The paper is tough as hell to tear apart. So more research on my end. Looked at a replacement fuel filter for a flex fuel tahoe and guess what... It's PAPER! Next I will pull the injectors to look for the "black goo" and check the status of that too.
Awesome! Keep the updates coming!