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I'm a fan of "Under the Hood Radio Show". Today, the topic drifted to flex vehicles and technology of these new model vehicles. The Nordstrom brothers akin to click and clack, but have better repair advice for vehicles and they appear to top of their game with up to date knowledge. The head advice brother claimed modern FFV much improved from the old days of losing 30% mpg economy. Ford especially. Current model vehicles tuned to exploit ethanol fuel benefits. Present day FFv only lose 10%-15% mileage on E85. He said if ever the engine and transmission were to be optimized for the fuel the mileage would be about equal. This guy would be rated the go to guy for mechanics that have hard to solve problems. The topic started per info that Ford's model T was a flex vehicle per the need of remote farmers lack of gas station. Farmers could brew moonshine to power the car. The car was able to burn a wide variety of fuels. The post was asking if Henry Ford was coerced to gasoline.  

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Transmission modified to max the efficiency of using E85?  I don't know what that is about.

 

In the past, a general statement  to maximize use of higher ethanol blends, you wanted:

  • higher compression
  • adjusted spark timing--don't modern engines have auto adjustment
  • modified fuel maps
  • modified engine computer unit and software.
  • larger fuel pumps/injectors

 

The first item is the biggest hindrance.    The modified computer unit and software  can control  invisible items.   The last item is just hardware with larger capabilities.    I can't speak about the first item with my background.

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The radio show didn't get that specific, but the transmission drive would need different programming to maximize the high torque ability of ethanol engine for MPG. The final drive ratio may be different. The spark advance of engine does change per engine sensor feedback to limit knock. As you know, gas fuel very touchy and can easily suffer preignition, but for efficiency they push ignition advance as far as possible. All the programming and engine strength/design is set to gasoline specifications as opposed to ethanol fuel. For example, I've read engine testing that found the injector duration a variable for engine controller to minimize spark advance. My guess the logic goes the longer injection of fuel for sudden acceleration will promote preignition and the engine controller needs to quickly lighten up on advance. Problem for flex fuel vehicles is the ethanol fuel will always lengthen injector duration. Yes, the test report had the fuel receiving reduction of timing advance as if the engine was burning gasoline. The engine was adjusting itself to run E85 in sub optimum condition. The test was rerun with manually setting ignition advance to E85 optimum advance with much improved MPG. I think auto engineers are handicapped with the traditional gasoline engine when attempting to optimize E85 fuel efficiency for all the things you post. When reading the Cummings  e85 engine report it became apparent the fuel is better suited to diesel engine strength and design. The fuel when optimized pushes combustion chamber pressure above that of diesel. Also, the torque (pressure) is double that of diesel. So, within optimal design the gasoline engine is a poor candidate. Think of a super strength diesel about half the size of normal engine sitting with two stage turbo for extreme boost pressure. This would be a spark ignition engine, might have air heater for cold temp startup and lower cold run emissions. It would run slower with same road speed. Compression ratio for this engine need only be 9:1. 

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For shift point rpm,  as long as engine isn't under extreme load  while running e85,  shift rpm can happen at  abit lower rpm.

( 1 or 2 mpg gain)

 

 I believe this is part of their finding at Colorado State Univ. ( and others, too). 

 

 If late model engines were equipped with knock sensors, this type of adjustment could be more commonplace.

 

Lacking an ethanol content ( %) sensor adds to the uncertainty.   VVT and Direct injection would be big pluses on the way to

10-10.5:1 CR.

 

Put all of these together, and suddenly E85 mileage penalty ISN'T...  Now if we could get the big 3 to pay attention .

 

Chrysler should actually be in best position to try all of this first...

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That Cummings E85 engine beat mileage of standard gasoline vehicle in all but the low horsepower duty cycle road tests. The engineers thought the ethanol engine needed a cooled EGR system. That would allow the engine to cut horsepower efficiency and achieve good mileage in this part of the test. We know diesel power is the cheapest fuel source for trucks and often cars per the high mileage. Problem with diesel engines the noise, weight, cost, and lower horsepower. The optimized ethanol engine achieves twice the torque density of diesel and surpasses the horsepower of gasoline. So, ethanol fuel has very attractive fuel attributes, especially when considering the reduced air emissions. Particulate matter a big problem with diesel engine. The optimized ethanol engine should be less expensive and lighter because of the small size and the Cummings engine achieved fuel cost equal to diesel with standard or representative pricing of E85.   

Edited by fleebut

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VVT and Direct injection would be big pluses on the way to

10-10.5:1 CR.

That's why I like my Ford Focus---it's 12 to 1 CR. Still getting a consistent 30 to 31 mpg on E85.

 

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I'm pretty happy with my wife's 2010 Impala,  last 2 tanks of E10 netted 29 mpg & $0.09/mile, 3 tanks of E85 before netted 24.5 & $0.07/mile.  16% loss in mpg, 32% cheaper fuel, and 22% cheaper per mile.  

 

Did a 200 mile day trip last month on E85, that tank was 26.5, I'd would have had to get 47 mpg with E0 that day to match $/mile. 

Edited by roosterk

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For shift point rpm, as long as engine isn't under extreme load while running e85, shift rpm can happen at abit lower rpm.

( 1 or 2 mpg gain)

 

I believe this is part of their finding at Colorado State Univ. ( and others, too).

 

If late model engines were equipped with knock sensors, this type of adjustment could be more commonplace.

 

Lacking an ethanol content ( %) sensor adds to the uncertainty. VVT and Direct injection would be big pluses on the way to

10-10.5:1 CR.

 

Put all of these together, and suddenly E85 mileage penalty ISN'T... Now if we could get the big 3 to pay attention .

 

Chrysler should actually be in best position to try all of this first...

The new 2014-15 GM full size trucks utilizes all this. An ethanol content (%) sensor, VVT, Direct injection, and a 11:1 CR.

I have a 14 Silverado and I also have a Diablosports tuner that I can adjust parameters. I've been using their flexfuel tune for awhile now and have seen an increase in 1mpg avg over the stock GM tuning.

I'm interested in your comment about lowering the shift points to further increase mpg. Do you have any further info on this? I could easily test this with my tuner.

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  Trying to find articles or anything published by the school(CSU).  I have contact info

 

  for the guys doing this E85 optimization work.  Also saw a table of values produced 

 

 from research , but it was more of a summary.  I think there are other schools pursuing

 

 similar data/results.   

 

    From my perspective,   we are missing the mark.  We already know the big three aren't

 

  interested in optimizing for ethanol .  So why not create a secondary market for those willing to

 

 invest in alternatives... to be "all in".. After-market conversions to run E85 only, or at least close to

 

 optimized for ethanol..  while we're at it ,  move the endpoint to e98.  

 

   Pass a stringent e-test ( IM-240 or better ) annually,  and you may run any blend you so choose.

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