I had a co-worker send me that list and asked me how the gas-only GM vehicles (as well as the gas-only Corolla and Civic) can be PZEV. I wasn't sure. I know MPG is weighed and maybe a cleaner-burning engine...but I thought partial zero emissions meant just that: sometimes (as when the engine is off sitting in traffic, not possible on a non-hybrid), it is a zero emission car.

I realize the Atkinson-Miller Prus engine is better combusting and the Hondas have a lean-burn (not sure what this means, but in an Otto cycle). So how do the gas-only cars do it using the Otto cycle? I was certain that the Prius is the only currently produced car using the Atkinson-Miller cycle for less emissions, but less power (thus using battery/electric motor(s) to fill the gap).

Any advice or internet sites to help here?

'04 Seaside Pearl #7. Fumoto oil drain, mudflaps, rear bumper scuff protector & rear warn system, compass mirror, EV mode button, 8" subwoofer in right rear cubby & 6" subs under seats, power lumbar in the front seats, Coastaletech hitch w/ Aspen bike/snowboard rack. iPod2car, 2 amps, Alpine component speakers, and DVD video, solid 47 MPG @ 70000 miles.