The graph above may or may not be impartial, I don't know. Seems legit enough for me as long as you take Bombardier and Airbus at their word for their new products. The CASM though seems to point towards the A320 as being the winner because it is a known quantity that will have some staggering 90 or 95% commonality with the current A320 and it's just being improved in the engines and drag. I think AW&ST said the A320 family would go from 4,000 or so to over 10,000 aircraft with the NEO. Whereas the C Series is still in the computer until it flies.
This is summer 2000 numbers:
http://www.icao.int/icao/en/ro/allpi...g4/wp28app.pdf
If you do the math and multiply fuel by 2 to 3 times you'll get closer to todays numbers.