Managing EGR for MPG

[omgwtfbyobbq]

I've posted this before, and when using a 1.9L TDI modified for SI and PFI, the maximum EGR rate was ~50%, and peak BTE ~43% on methanol, and ~41% on ethanol, which is much better than the Prius' 37%, and more importantly, on ethanol 38% efficiency is seen as low as ~7 bar from ~1.2-1.8k rpm (fig.4), which means that efficiency is ~1.5 times that of the best gasoline engine available during he EPA highway cycle.

Since the price of E85 seems to correspond to it's lower energy rating per gallon, this implies that a Prius powered by one of these engines, running on E85, would probably get ~55mpg of E85 on the EPA highway cycle, or a fuel content adjusted rating of ~77mpg. So as long as the price of E85 is less than 87 octane gas, it would be more efficient, and definitely cheaper, to have this type of engine.

It appears that the limit in terms of minimizing pumping losses via EGR is primarily engine design, and then probably the octane of the fuel. Is anyone else thinking about an intercooled EGR valve?

edit- Oh wait, the University of Wisconsin already did for some parallel diesel hybrid project. But no mention of it's use for gassers, I wonder why...