I stopped by for a free cup of coffee one morning and spoke with one of the salesmen about the engine. It weighs a lot!!!!! He didn't envision a large market for it because of the weight and complexity.
If fuel burn is 11% less then 100 pounds less (14 gal) of fuel would meet exact mission. 120 gal in a Malibu would be 106 gal now. Wrong W&B, but that is another issue.
They don't talk about compression ratios etc. The fuel efficiency will be challenging if the high boost pressures required a drop in compression ratio to meet cylinder pressure limitations. The same goes for retarded timing but that would increase compression pressures too.
It will certainly be interesting to see how this is progresses. Too often, optimistic claims have not delivered. It is not an easy job. A clean sheet engine, even a derivative, will have to be validated, gasoline test procedures will not yield a satisfactory result.