The only thing that makes it get 42 mpg is an overdrive on the 6-speed auto box (it is not available with stick-shift) The LT gets 36 mpg, because it doesn't have the OD.
The engine is a 1.4 with turbo giving 138hp, and the cars' weight is close to 3100 lbs. So the power/weight ratio is just a bit worse than ours.
Actually, the ECO is ONLY available in a manual transmission.