Gas Mileage for 117 mile stretch: Average 34.5 MPG
Trip Average: 255 miles, 31.57 MPG. Did a bit of running around between the two, long highway drives.
Used an OBDII scan gauge to get the above information.
Your SE is definately having some issue'* if your still averaging that low. I'd try to gain access to a nice OBDII realtime scanner to check out specs once your vehicle is fully warmed up, it will tell you a lot of information.