Just out of curiosity, what fuel brand do ya run? It makes a difference. ARCO sucks, Union 76 uses some ARCO. They are high in alky. When I raced Karts we could not pass a fuel check with ARCO. They read more alky. This results in less MPG. I use Chevron. One of the OEM's I worked for tested fuels and only recomended it. If you didn't use it you would get build up on the valve stems and it had to be blasted off.

As far as driving around. Short drives will net lower MPG readings on the DIC.

I drive from Burbank to Cerritos and with my '08 2.4 5spd panel I'm always 29-34 mpg hiway averages on regular gas.

This week I'm in Texas and rented an HHR w/auto. With a/c on and 60-70mph the DIC says 27 average.