[Jim-Bob]

If maximum mileage for the minimum price is what you seek, a Geo Metro is what you need. They are available in a 4 door and so long as you get a 3 cylinder with a 5 speed it is hard NOT to get 40 mpg out of one. You could also look for a Civic VX or the very reliable B13/B14 Sentra with the GA16DE/5 speed too. The Sentras are worth 30+ MPG city if in a good state of tune and they have timing chains, not belts. Typically you can expect a Sentra that is well maintained to be capable of 300k+ miles due to the high nickel engine block, forged crank and rods and timing chain. I am not a huge fan of Civics because the engines tend to be more fragile than the ones used in Sentras, but the VX's lean burn engine makes it worth the risk as they get almost the same mileage as a 3 cylinder Metro.

For prices, Metros can be anywhere from damn near free up to $5,000-depending on where you find them. I paid $250 for my 1991 3/5 4 door and it runs and drives. My 1992 3/auto 2 door was $350 and it needs an engine. Both my cars were Craigslist finds and were listed as needing work or as parts cars. However, the important thing with a Metro is not the engine ( they are cheap to go through) but the chassis. You need to check them over VERY carefully for rot in the front where the lower control arms bolts to. I would also shy away from an automatic car unless you have a 5 speed parts car. The automatics give up 10-15 mpg to the 5 speeds and can be expensive to change over (around $300). However, if all you can find without rot is an automatic, take it and try to get a 5 speed parts car.