9.1ga/331 miles= 36.3 MPG. Roughly 75% highway 25% city....anyway I can improve these numbers or does that seem about right? I figured I should clean my injectors soon anyways, I have heard of a product called BG something that works excellent.

 

Seems very good for a non-vx or cx model.

 

Your numbers seem consistent with what fueleconomy.gov says. See especially the actual reports that people have submitted.
Three things I am focusing on right now to improve my 93 Civic's MPG:

--Running a bottle of Chevron Techron through my 93 Civic's fuel system for each of the next four tanks of fuel
--Considering a new ECT sensor. I have a report from someone else that these age quickly while not throwing a CEL, and a new one can improve gas mileage.
--Considering a new dizzy housing. It is only about $100 for an OEM one my Civic (OEM is a lot more for other Civics). I think the three sensors inside the housing degrade over time arguing for replacing the housing say every 10 years/150k miles.

Here are the other items I watch: http://honda.lioness.googlepages.com/gasmileagetips

 

i dont know exactly how many gallons my 92 civic lx holds but i fill up with $20 and drove 365 miles thats punching it quite often and mainly street driving and 30% highway.
it has a d16z6 engine with dc sport header and cold air intake only.

and by the way this is open header dc sport. since people say you loose gas milege from no backpresure. it is cut off at the downpipe.