Shouldn't I be getting better MPG

[samasaurus]

My 89 Civic STD HB now has an 89 CRX HF California edition 5 speed. I drove around town a little and then to work and back and put on about 200 miles and got around 41 MPG. Was hopping for a little better but it still need an alignment. So I hopping that helps a little. The final drive is 3.25 witch is the same as the vx(I believe). so I am going to call it an 89 Civic VX. I also put in fuel injector cleaner because it would run rugh and die at stops every ounce in awhile(not all the time).Would the injector cleaner affect MPG badly?Could this be form a bad O2 sensor? Mine also dosent have v-tech. Dose that make that much of a diffrence. Mine is only a 1.5 Liter. Shouldn't I be getting better MPG.