Back when fuel was $2.50ish a gallon (about a year ago) in my area WNC, I would fill up everytime I got paid. The last time I attempted to achieve the best MPG, I filled the car up, and drove it like a old man.
My goal was to get 300 miles on a tank of gas. After pulling out of Taco Bell, and getting on the by-pass, I looked at the fuel and odo 1/16 and 273 respectivley. I thought yep, I'm going to do it. Umm Nope...at 278 miles, with 1/2 a 1/2lb cheesy bean and rice burrito in my hand, I'm pulling into the emergency lane 1 mile before my exit because its running out of fuel. No gas light (always comes on otherwise) and a needles width of fuel left. So, my point is...**** MPG, get a Civic or Corolla if money is tight, but dont drive your FC like one. They hate to be babied. So, the next tank of fuel was slung through the engine like it was the last 16 gallons on earth, and everyone was out to take it from me. Well, I still got 241 miles out of that tank. I just drive like I want to, but I will admit that $4.17 a gallon hurts alot worse now. When I'm broke I drive the MX-5, just as fun but in a differant way 25 mpg.

 

hold on so these cars is with emissions on them? or with out?

 

Mine was definately without an air pump, but still had stock cats.

 

No Smog pump, No Cat, removed A/C, removed factory airbox and replaced with cone filter.

Non DOT approved race header, 3'' exhaust into pre-silencer, Y-off into two Ractive mufflers.

IMHO by me removing the old manifold (not real efficient anyways) and exhaust
it actually helped somewhat with mileage. If you live in a state that has doesn't have strict emission standards, remove the cat!

As Icemark stated, these cars are not much worse that modern sports cars in the MPG dept. Also, Mazda made due with 1.3L while Toyota, Mitsu, and Nissan all used 6 cyl to achieve the same goal. 13B makes similar power w/ less displacement and weight. I had a 85 Celica Supra and an 85 300ZX, and they both sucked fuel at the same rate.