Usually I am NOT for using E-85. With the reduced mileage associated with the lower energy content, the cost tradeoff is generally not worth it. Generally.
However, you have to recognize the current state of gas prices. Ethanol has been running about 50 cents more expensive than CBOB. That said, a lot of stations are still discounting E85 – as much as 50 cents per gallon. Locally for me, a Kroger station I saw yesterday was selling RUNL for $1.68 and E85 for $1.18. A 50-cent discount on $1.68 amounts to about a 30% discount from regular unleaded. Even considering a 20% drop in mileage, that’s a pretty good deal. Throw on a Kroger fuel discount on top of it and you’re really doing well. Considering that Chicago wholesale prices for straight ethanol are about $1.50/gal, $1.18/gal is actually BELOW COST.
Check prices near you to see if it’s time for you to consider using E85. Also make sure your car is able to use E85 as it can wreak havoc on an unqualified fuel system.