What kind of gas milage do you get on your 300 sixes? I have a 1993 F150 automatic, extended cab, with a shell...i never tow anything with the truck. Most of you say that you get 10-12 mpg while towing....then why do I get that same gas milage without towing? As a daily driver its getting hard to keep up with rising gas prices...what can i do?

The idle is kind of rough...i've recently replaced the spark plugs to no avail and also the fuel filter. It hasn't been checked for timming, and i think they said the sensors are okay. I've never brought it in for code checks and the engine has not been tuned up regularly. Just the normal oil change is what my dad has done for the past 7 years. MAN! 12 MPG suck for a 6 cyl. I have frends with 351s with the same gas milage!