I think the '04's are flex fuel. I know the '05's are. You can open your fuel door, and there'll be a sticker that says so if it is. If you can find the e85 then you just pump it in. My owners manual says to only use half a tank the first time you use it if you have unleaded in it now. It's suppose to help the computer make the adjustments. Also it claims if you use e85 more than 50% of the time than you should increase the oil change interval. I've posted that before though, and someone said that it wasn't right.