Interesing article.
If in fact it's true as DAN says that the EPA won't permit a second tank needed to improve efficiency or reduce emissions, how are they handling the urea tank that VW and MB are using in their cleaner diesel vehicles?
I could see something like this ethanol injection taking hold, because the vehicle owners have a
self-serving incentive to keep the secondary tank full: more power and higher efficiency. The car's computer would simply dial back the power and increase fuel consumption should the ethanol run out.
This is unlike the owners of urea injected diesels, whose only incentive for keeping their urea tank full is "to help keep the air clean". (Hmmm, maybe the EPA needs to decree that urea-equipped diesel computers must dial back power if the urea runs out
)