Increase MPG

I have a Ford F-150 at the moment that I am in the process of selling. I will then purchase my sisters 323 from her. I'm not exactly sure what kind of MPG it gets. It is a 2000 model. I was wondering if anyone knew of a chip or other mod I could do that would increase the fuel economy of the vehicle. I've just gotten a new job all the way across the state and will be doing a lot of road miles. So better fuel economy would be nice. Thanks for any input.
Duck