Poodles;1985883 said:
Driving and using the E85 isn't the issue, it's when it sits and has time to accumulate that water that it's an issue.
This part is correct and it also requires temperature changes for condensation to form. If you're running E85 and you let your car sit all winter (4+ months) then you should probably drain the tank. I have a couple of friends that let their cars sit with half tanks of E85 all winter and they started and drove fine, but I wouldn't recommend that. Other than that it's not an issue.
Poodles;1985883 said:
There's many other issues with E85 though. Eats a lot of things, it's too "dry" and doesn't lubricate properly, it's not consistent enough to really tune correctly on, etc.
This is all incorrect. Hundreds of cars are tuned and run perfectly on E85. You should, however, regularly test your E85 with a 15 dollar tester from Summit and be aware of the changes from winter to summer blend as well as run a pump and filter that is E85 compatible.
Poodles;1985883 said:
Bzzz wrong. Water in the fuel system was an issue before they started adding ethanol to our gas, now it's even worse. E85 takes that to whole different level.
I don't know where you get your gas if water is always an issue, but you might want to switch stations.
Bottom line, if you let it sit for months then you might have condensation issues, just like you would with any fuel. Unless you’re stupid, E85 is simple to use. Whenever I see a bunch of E85 misinformation it comes from people that don't run it. Myself and MANY of my friends have been running it on all kinds of different makes and models for 5-6 years and nobody has ever had an issue related to its use. Well.....other than being able to run more boost thanks to a severe reduction in knock and intake air temperatures.
As for the OP's question, water/fuel separators aren't expensive and if you'd rather have one for peace of mind then sure, why not. But it's definitely no more necessary to run E85 than a flex fuel setup is.