What do you guys think?
I think all these engines are relatively comparable and that the fuel economy has less to do with the engine design than with the transmission design, if it is an automatic. My 2009 Aveo gets lousy FE in city driving (at any speed under 45 MPH), 22 MPG at most. But once the torque converter locks up at 45 MPH it gets 37 MPG. It's a four speed automatic and the brilliant engineers at Chevy programmed it to have the same delayed shift points as all the other gas hogs they produce. That gives the Aveo decent acceleration in the lower gears, but at the price of poorer fuel economy.

Chevy pitched this car to rural America with a high highway MPG, and it really does achieve it at highway speeds - but if you are a city dweller who does no highway driving the local fuel economy sucks, especially for such a small car. Honda and Toyota apparently are using a more sophisticated transmission (probably a 5 speed?), or at least one that is programmed to lock up much sooner than 45 MPH. The Versa and the Rio are about the same as the Aveo when it comes to relatively poor MPG.