Eco-Boost Flex-Fuel (E-85/Gasoline) Engines With No Mileage Penalties Would Decrease Oil Imports

The use of E-85 (85% ethanol) fuel in “Flex-Fuel” vehicles has been limited by its 25 percent lower energy content than gasoline. When used in engines designed for only gasoline this results in approximately 25 percent less mileage for a fuel that costs as much as gasoline. So, unless E-85 costs 75% of the price of gasoline (If gasoline is $2.65/gallon, E-85 would have to sell at $1.99/gallon) there will continue to be little demand for E-85 and little reduction in our use of imported oil.

Enhancements, primarily software and sensor calibration, to the Eco-Boost engines could utilize the higher octane of ethanol to resist early ignition thereby increasing thermal efficiency that would regain much of this fuel economy loss. Possibly even more important, these engine designs produce increased low speed power (torque) when using E-85. This torque increase allows lower-cost E-85 engines to replace more expensive diesel engines in light-duty trucks such as the Ford F-150.

Achieving improved thermal efficiency with E-85 or, similar ethanol concentrations, is however, just one side of the equation. The other is building a “Flex-Fuel” engine that can achieve high mileage with lower octane gasoline as well.

Fortunately, the Eco-Boost engine family combines comprehensive computer engine controls involving multiple sensors and actuators, direct fuel injection, sequential turbocharging technology, and some previously overlooked historical engine designs, that allows these two seemingly competing goals to be simultaneously met.

The widespread use of these engines in both automobiles and light trucks would result in a significant reduction of imported oil which would greatly improve our Energy Security. Equally important, this demand would be met by cellulosic E-85 that would be produced from sustainable, non-food biomass. It is also very important to realize that this market would be a sustainable, rather than an artificial subsidized market, since it would be based on vehicles having equal or superior performance characteristics to gasoline or diesel powered vehicles.

Kickit J 07/12/2014
Yes!  It's just about impossible to find a turbocharged e85 vehicle.  I just read an article that the 2011 Buick Regal has is a flex fuel turbo.  Ford, sell the performance of 105 octane e85 in a turbocharged hatchback!  I would buy that!
heath 04/14/2013
I have been waiting for Eco-boost engines to be Flex fuel for years. i am get sick of all car manufactures that won't put their turbos on E85 or make them flex fuel. even Buick that has the turbo Regal doesn't put their best turbo Regal on E85. the first car that is 4 cylinder direct injected, turbo charged, AWD, and flex fuel will be purchased by me regardless of which manufacture makes it.
MPW 04/13/2010
Absoulutely! In Midwest farm country where E85 is relatively easy to get, relatively on par cost wise when considering BTU equivalent, having an engine that can be optimized to e85 fuel will be a winner. It won't take farm community folks very long to do the math if they had a pickup that was optimized for e85 actually gave lower costs per mile with the subsidized e85 price differential from regular gas. The GM/Saab biopower options in Europe have shown how easy it is to have a car that is optimized to run on e85 can get comparable MPG when you use timing and varible boost available from the turbo to leverage the inherent octane benefits of e85.

It is not just good enough to have material compatibility to e85, you should work to optimize to e85, at least in vehicles that sell in farm country!