HORRIBLE Gas Mileage...HELP!

My 96' lantra wagon is only getting between 17-19 MPG. This is horrible. I've gotten an oil change and put cleaner in the gas to clean the internal parts that may clog.

Any help would be VERY much appreciated!

That's absolutely the expected milleage at heavy traffic.
Mine is a1997 Automatic sedan and that is the performance.
And it is 100 % O.K. and with only 60.000 miles.