Some years ago Honda tried something called a "Stratified engine"?
 

The car that they tried it on was the Honda CVCC and it got upwards of 52 mpg as I remember. That was back using carburators, and timing belts to run everything, and it was very easy to get everything out of sync. Now I'm no mechanic , but with efi and all the other scientific advances in automotive technology it seems that the stratified engines time may have come. Is anyone seriously working on this system?