im getting 210 miles on a full tank, car has 109k miles, any suggestions?

 

How old is your o2 sensor, a worn out one will really affect your mpg.

 

Sigh,

please, please, please... learn something about your car before you ask something sooooooooo broad.

My first suggestions:
1. Don't drive
2. Don't push the pedal so far down.
3. Don't race.
4. Lose the sports car. To make power, ya gotta burn fuel.

Now, beyond that, you first need a goal. I have found 22-24mpg to be the best your gonna get from a stock motor. The first thing to check is your state of tune. Don't know how to tune up your motor? Go purchase a haynes manual(chiltons or helm is better) and learn how to change a spark plug.

Once you can absolutly say your motor is in EXCELLANT tune, search in the general tech forum for "mpg" or "milage". Your answers are waiting for you there.

 

Assuming you're talking about the TBI car, the first thing I would check is the fuel injectors. They're a common failure. Then the O2 sensor, spark plugs, and wires.

My dad got 28 MPG with his 305 TBI stock, then 30 MPG after converting to TPI. It is possible.

 

I've actually never heard of TBI injectors failing, maybe getting dirty but that isn't anything a bottle or two of fuel injector cleaner won't fix. Common things are egr valve, O2 sensor, air filter, exhaust leaks, ignition, and the number one leading cause of bad mileage is a heavy foot, like pizza guy said check the mpg threads and if you still have problems then try a new thread and state what you've done to try and remedy. Sorry if this sounds harsh but it is a very common subject.

 

I have found that my TBI 350 Van is regularly knocking on 20 MPG on the highway. 30 out of a TBI F-car is definately within reason. Current engine mods in Sig.