What I did was filled the car and drove 127 miles (highway, city combo) When I filled it back up it took 8.8 gallons.
This gave me 14.4 miles per gallon. This was after the tuneup but I do run the A/C all day and night.

What do you guys think.....? Too Low or what ?

 

Could be better. Combined city/highway I get 19 MPG, but then again I have a 305 and I don't have a lead foot (well, I do when I want to, but that's not very often).

 

Highway/city combo doesn't tell us anything useful. How much time was spent idling a at traffic lights? How much time was stop and go with ore stop than go? You really can't do a lot to improve city mileage beyond controlling the urge to see if you can better your 60 foot times at every stop sign or light. You are right, you need to fill the tank and take the car out on the highway. Maybe join the Inland Empire guys on the Idyllwild cruise, and check your mileage on a long open highway run. If mileage is an issue to you, you need to get a second vehicle. Get some sort of used beater 4 cylinder, maybe even a compact pick up, and use that for a daily driver.