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MSNBC picks up on MIT's Ethanol injection system - 20% to 30% better mileage using less ethanol!!!

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JohnWxy Donating Member (1000+ posts) Send PM | Profile | Ignore Wed Nov-01-06 05:33 PM
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MSNBC picks up on MIT's Ethanol injection system - 20% to 30% better mileage using less ethanol!!!
Edited on Wed Nov-01-06 05:48 PM by JohnWxy /

BOSTON - Injecting small quantities of ethanol into car engines at moments of peak demand -- such as accelerating sharply or climbing a steep hill -- could improve the fuel economy of gasoline engines by 20 percent to 30 percent, according to MIT scientists.

A team of researchers at the Massachusetts Institute of Technology is working on the system, which scientists say would allow carmakers to use smaller engines in their vehicles, reducing weight and improving fuel economy at a lower cost to consumers than by adding a hybrid engine.

To have a big impact on reducing oil consumption, one needs a low-cost way of improving efficiency, so a lot of people buy the car, said Daniel Cohn, senior research scientist at MIT in Cambridge, Mass.

He estimated that adding the ethanol injection system to a car would cost about $1,000 and that cars using the new system could be in mass production by 2011.

We view it as a very important near-term way to reduce oil consumption, Cohn said.

"very important"??, 20% to 30% fuel economy, using far less ethanol - for $1,000 per car?! Professor you've got a gift for understatement!

Apparently ABC News reported on this too: /

MIT researchers developing an on-demand ethanol injection system
Posted Oct 25th 2006 6:57PM by Derrick Y. Noh
Filed under: Ethanol

According to Reuters, a group of researchers at Massachusetts Institute of Technology are working on what they think is a more logical ethanol solution for our impending fuel crisis. Instead of using ethanol as a primary fuel or an additive, we could potentially see more realistic fuel-saving improvements across a wider spectrum if we implemented a system on cars that injected ethanol in small quantities when the engine is under heavy load.

The idea is to run a smaller, more fuel-efficient engine in your car while maximizing the usage of the higher octane ethanol so as to not impede performance. The group estimates gas mileage improvements of about 20 to 30 percent and Daniel Cohn, senior research scientist at MIT, says that adding the ethanol injection system would roughly add $1,000 to a vehicle, considerably undercutting the premium for a gas-electric hybrid.

It seems like a novel use of ethanol, since the renewable fuel's limited supply is often the first argument used against its sustainability. The source article is rather short, though. When discussing how the system works, they only state that it would be used on a turbocharged ICE and that the ethanol would be injected when knock is likely to occur. They don't discuss the turbo in any level of detail, but one might consider that it may make sense to incorporate a system that would advance the timing and increase the boost pressure when the ethanol is in use like that of Saab's biopower system. As for the amount of ethanol required, Cohn doesn't offer an estimate, but says that it would only have to be refilled about every three months.

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

D.R. Cohn*
L. Bromberg*

Ethanol has a high fuel octane number (a blending octane number of 110) 2. Moreover,
appropriate direct injection of ethanol can provide an even larger additional knock
suppression effect due to the substantial air charge cooling resulting from its high heat of
vaporization. Our calculations indicate that by increasing the fraction of the fuel provided
by ethanol up to 100 percent when needed at high values of torque, an engine could
operate without knock at more than twice the torque and power levels that would
otherwise be possible. The level of knock suppression can be greater than that of fuel
with an octane rating of 130 octane numbers injected into the engine intake.
The large increase in knock resistance and allowed inlet manifold pressure can make
possible a factor of 2 decrease in engine size (e.g. a 4 cylinder engine instead of an 8
cylinder engine) along with a significant increase in compression ratio (for example, from
10 to 12). This type of operation could provide an increase in efficiency of 30% or more.
The combination of direct injection and an a turbocharger with appropriate low rpm
response provide the desired response capability.

Because of the limited supply of ethanol relative to gasoline and its higher cost, it is
desirable to minimize the amount of ethanol that is required to meet the knock resistance
requirement. By use of an optimized fuel management system, the required ethanol
energy consumption over a drive cycle can be kept to less than 10% of the gasoline
energy consumption.

This low ratio of ethanol to gasoline consumption is achieved by using the direct ethanol
injection only during high values of torque where knock suppression is required and by
minimizing the ethanol/gasoline ratio at each point in the drive cycle. During the large
fraction of the drive cycle where the torque and power are low, the engine would use only
gasoline introduced into the engine by conventional port fueling. When knock
suppression is needed at high torque, the fraction of directly injected ethanol is increased
with increasing torque. In this way, the knock suppression benefit of a given amount of
ethanol is optimized.
The most recent estimate for the energy output/input ratio for ethanol (energy provided
by the ethanol divided by energy needed to produce the ethanol) is 1.67.3 For the
illustrative case discussed above, the ethanol energy contribution could be effectively
increased by a factor of 4.6 which is the ratio of the leveraged energy output value (3.2
gallons) to the substitution energy output value ( 0.7 gallons). In this case, the energy
output/input ratio would be 7.5. Hence the economic value of ethanol could be greatly


The DI ethanol boosted gasoline engine concept could provide a cost effective way to
meet near term goals of reducing gasoline consumption and CO2 emissions by 30 percent.
The fuel savings payback time for the increased vehicle cost of approximately $600 could
be about 2 years. The energy output/energy input ratio for ethanol could be effectively
increased from a presently estimated value of 1.67 to a much greater value.

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