What system will tell me instantaneous MPG on a 93 VX?
 

What system will tell me the most accurate, instantaneous MPG on a 1993 Civic VX? MPGuino? ScanGuage? It should only need to measure fuel amount and rpm to get the data it needs.

The SG and UG work off of the OBD-2 bus in the car. Which is only present in 1996 and later cars, so your 93 won't work.

The MPGuino is pretty much your only choice. (Or SuperMID, I hear, but I also hear it does pretty much the exact same thing as the MPGuino.)

-soD