When I had my V6 5sp SE, I drove up to T.O. with my car FULLY loaded... it was almost on the bump stops. Running premium gas and going a max 110km/h my average was 700km. I didn't want to push it when the light came on, I was in the states (White Mountains) not where I'd want to run out of gas.
The V6's like to run at 3000rpm for best efficinecy.