I use many of the same driving techniques outlined by lessevildave to improve MPG's when driving my 92 Honda Civic CX hatch (with 375,000 miles on it). I don't have any fuel consumption gauges (or even a tach) on my dashboard, so I use the number of miles traveled when the fuel gauge needle hits the half full and empty marks on the gauge to get an idea of my mileage before I calculate it when fill up. Since I don't have an ICE capable of lean burn, I try to do as much of my acceleration and hillclimbing as possible at about 75% throttle where my ICE runs most efficiently, following by freewheeling on the downhills or when I know that I am going to have to slow down for traffic, lights, etc. I also shift gears to keep my RPM's below 2000 when accelerating and don't go over 3000rpm except when climbing a steep hill. On some long downhills that aren't steep enough to require friction or engine braking, I will shut the engine off until I reach the bottom. I get my best mileage on rolling terrain where the downhills aren't steep enough to require braking.

Some additional MPG tips: When the roads are so wet that vehicles leave tracks behind on the wet road, try to drive with your wheels following the tracks of the preceeding vehicles to reduce the MPG robbing drag of the road water.

If you are driving into a strong headwind, drop your speed 10 miles per hour or so to get yourself out of the steeper part of the aerodynamic drag curve. When you drive at 65mph into a 35mph headwind, your car is getting the drag it would normally see when driving at 100mph. If you can reduce your speed by 10 or 20 miles per hour, then you are only driving at the equivalent of 90 or 80 miles per hour, aerodynamically speaking.

It has been getting more difficult to find tires in my OEM size (165/70/13), so I've had to go up to the next larger size (175/70/13) and do some experimenting to try to avoid the MPG drop caused by the larger, draggier tire. I 've found that if I raise the tire pressure about 10psi above the maximum listed on the sidewall, I get the same rolling resistance (and MPG's) that I did with the narrower tire and yet I am still getting much improved cornering and braking performance than I got with the narrower tire. I suspect the tire is riding up on the center somewhat, reducing its footprint to about that of the narrower tire when driving straight ahead, but when I put a lateral force on the tread (when cornering, braking, or accelerating) the tread flattens out out its full width. I got 70,000 miles from my last set of tires run at these air pressures with better handling performance than I did with the OEM size tires.