MPG readings on older vehicles?
 

Is there a way to get a hyper accurate fuel measurement on vehicles before all the modern OBD2 and later type stuff? Carburetors, older fuel injection, preelectronic diesels, etc.

Note i'm referring to realtime measurement.

My Datsun falls into the "older fuel injection" category.
I have an MPGuino that I'll be fitting once I can add a reed switch to the speedo, to act as a vehicle speed sensor.
The injector signal is already present in this case of course.

For anyone interested, this link shows one way of adding a VSS.
Adding a VSS output to a Mechanical Speedo (reed switch)

Pete.