Mileage (mpg) Using Ethanol Seen 20% Higher Than EPA Says - Bloomberg

[Bill USA]

22. three MIT scientists designed a DI turbocharged engine with ethanol (DI) that gets 25-30% better mpg

than typical ICE on gasoline. But only about 5% of the total fuel usage is ethanol (it is directlly injected into the combustion chamber).
Ethanol injected into the combustion chamber enables higher boost from the turbo - not just because of higher octane rating (~113 vs gasoline's 86-94) but also because of ethanol's higher latent heat of vaporization cools the air-fuel charge in the combustion chamber. This enables higher boost pressures (the higher latent heat counter-acts the heating induced by higher compression).

see: Ford E85 Direct Injection Boosting Study: A Less Expensive Alternative to Diesel

http://www.greencarcongress.com/2009/04/ford-e85di-gasolinepfi-20090426.html#more


Here's a paper by mssrs Cohn, Bromberg and Heywood:

Direct Injection Ethanol Boosted Gasoline Engines: Biofuel Leveraging For Cost Effective Reduction of Oil Dependence and CO2 Emissions

http://www.ethanolboost.com/LFEE-2005-01.pdf

Now, one thing to be considered in any new technology is cost - because that affects how readily adopted it will be. The marginal cost of the Ethanol Direct Injection engine they estimate to be from $1,000 to $1,600 mass produced. This is about 1/3rd to 1/4th the cost of a conventional hybrid while offering similar mileage gains. This would be much more readily (read quickly) adopted by consumers.

And time is of the essence. We don't have 20-30 years to weight for a 25% reduction in aggregate gas consumption by the light transportation sector. By substituting ethanol and methanol for gasoline we can get to a 255 reduction in gas consumption much much quicker than weighting for people to buy enough electric cars (including conventional hybrids) to achieve that much gas consumption reduction.

The cost of oil/gas will sink our economy much sooner than we can get enough electrics on the road to get enough of a gas consumption reduction.