I just bought the vehicle. Head gasket was just replaced and it was tuned up. There is no smell of gas coming from anywhere. The check engine light is not on. I am getting about 14 miles per gallon on mostly highway driving. It appears to be running quite well, but I'm getting about 1/3 less fuel economy than I expected. Any ideas would be appreciated. I'm thinking maybe the fuel filter? If you need more information, please let me know. Thank you!