Gas Reg Prem or Plus?

What is the best kind of gas to run in my 2008 GTS Lancer? And if the
Gas contains ethanol is that a good thing for your motor or bad? The 08 Lancers motor is Aluminum and I don't want to burn it up. 
 
   I have bought all my gas at Costco here in Portland because they seem to have the best gas I have found there regular gas makes your car run better then shells prem. I didn't think Costco would be good when I had my last car I though I would try it turns out Costco has higher standards for there regular then Shell has for there premium gas. I guess that is why they have the lines and there price is a few pennies cheaper. I don't buy gas at anyplace other than Shell or Costco and so far with my new car I have only bought at Costco.
 
I will never buy gas at Arco, BP, Exxon, 76, Conaco Phillips or flying J because I have herd there gas is crap. Cheveron I have had mixed results with. Bottom line were should I fillup and with what is costco reg bad?
 

Your car should be set up to run with ethanol.
I don't recommend you to use anything but what is intended for your motor.  Don't use premium if your car requires regular.  You have a new car with a new motor...tell me what this "better" is. 
What kind of gas is recommened with your 08.

costco rips u off in gas here in az...they short u...proven

As far as ethanol goes, most companies are using a mix of 10% ethanol and conventional gas, I wouldn't go ahead and pour pure ethanol in there, but a 10% mix is fine. As far as the best gas companies go, I only trust shell, its always talked about in every car forums I go to as having one of the best additives and thats including "regular" wich is what I use. Using premium gas unless stated in the manual is just a waste of money IMO.

In fact you can safely use e15 which is 15% ethanol mixed up with fuel, you should however make some mods to your engine to be able to run on e85 which is 85%, if im not wrong, fueling up e85 on your engine will cause it to run insanely lean.

Kaede is absolutely correct, any motor built can be set up to run on e85, however you will have to change all the filters and injectors and have your computer programed to run it, however this may void your warranty, since it can be classified as an engine mod.

Thank you, i kinda know about it cuz were doing a work about it at college, and being too much time in this forum has kinda taught me to realize how ethanol kinda works hehe, but bout the regular fuel is better to use silver's advice cuz of the octane and compression article he posted that time here

use only 87 octane fuel from any manufacturer.  do NOT waste money on premium.  Its of no benefit and actually can cause drivability issues in cars not designed for it.
NEVER use e-85, as your car is not designed for it and will run poorly (if at all).