what type of gas do you use in a 2009 town and country 4.0L is it flex fuel

Means you can use E-85 Instead of just the common E-15 and of course fuel without ethanol. Not diesel.

Regular gas will work just fine, E85 will reduce your mileage a LOT!

Willkapedia says In the US, only since 2008 FFV models feature a yellow gas cap with the label "E85/Gasoline" written on the top of the cap to differentiate E85s from gasoline only models. Flexible-fuel vehicles (FFVs) are based on dual-fuel systems that supply both fuels into the combustion chamber at the same time in various calibrated proportions. The most common fuels used by FFVs today are unleaded gasoline and ethanol fuel. Ethanol FFVs can run on pure gasoline, pure ethanol (E100) or any combination of both.

Exactly, Pure gas no ethanol means better MPG & higher cost, the higher the ethanol rating the cheaper the fuel but lower MPG.

Yeah but e 85 is 104 octane...significant power difference