All I know is that when I'm running my non-Atkinson cycle Corolla engine at a steady 40mph, I'm getting between 65 and 75mpgs. If you use the
current EPA driving cycle to measure a car that uses batteries only for 40 miles of driving, improve the efficiency of the engine my using an Atkinson cycle engine designed for a narrow rpm band, then 230mpg, using the current EPA test cycle, looks quite achievable, assuming a charged battery.
The real question is: What is the MPGe? When you count the power from the outlet, how does the number look?
How much is your bridge?