Does anyone know of any 80's or 90's cars that have really good gas mileage. I've heard that Civics and VW Rabbits got like 40 or 5 MPG before catalytic converters.

My 1993 Civic DX gets 42 mpg around town and up to 56 mpg on the road (if I try to max it out at 55 mph). I use Mobil 1 full synthetic 5W-30 engine oil and Amsoil synthetic 5W-30 manual transmission fluid in the transaxle. The high temperatures in Texas help my gas mileage. I have a catalytic converter and my car's 2008 emission test results are:

High Speed Results:
. HC (PPM): Standard 220, my car 6.
. CO (%): Standard 1.20, my car 0.01.

Low Speed Results:
. HC (PPM): Standard 220, my car 7.
. CO (%): Standard 1.20, my car .03.

These results clearly demonstrate that cars can get great gas mileage and preserve the environment, even if the car is 15 years old. The results on my Civic are the same as if the car were new. Emission results are the best overall indicator of the engine's health and your preventive maintenance program. The key has been synthetic lubricants, since day one.

Wow! And you didn't modify the engine or anything, that's really incredible. So why has that decreased? I have an '03 Civic DX and I only 30/33 MPG.

No mods. Can't really tell you. Mine is only a 1.5L engine.