Yeah, I just bought a 96 LS, and I too have noticed the gas mileage being kind of bad (im used to my 93 civic si )

I got it two weeks ago, and the guy put new plugs,distributor, and a whole tune up, and everytime he had an oil change he just got a whole tune up so it theoretically should be fine.. Maybe its my filter or something?

I'd try to drive let erratic but my first gear feels kind of weird, like i have to get over a little hump in the road before it goes or ill stall.. maybe my civic clutch was just too light?

Edit: I forgot to point out i'm borderline 200k miles, and since it's an LS, no vtec