Yup. Looking to release within the month... green month over at the magazine.
The results, however, merely reinforced the need for me to purchase a ScanGauge or something similar. Trying to validate theory via a tank-to-tank fill on the spot is incredibly frustrating, to say the least. Need several fill-ups to corroborate data, and the time it takes means that traffic and weather variables will affect the later runs considerably.
Already knew that going in. On my personal car, I've seen fill-ups vary by up to a liter (about a quart) depending on the temperature of the fuel rail and whether the return system decided to dump hot fuel back into the tank when you put the key in the ignition. As it is, I tried my best!
A friend recently pushed for a weight-based economy measuring system:
Chevrolet Spin tops CAGI fuel efficiency rating
It has the potential for great accuracy, but requires the AC be off (condensation adds weight) and the resolution of the scales requires you to run about a hundred kilometers per test.
That's a whole lot of kilos to run.
I also have my own issues about the aggressive acceleration profiles required by the testing route (evident by the ultra-low score for the Spark!), but that's something for another time.