Flex Fuel Engine Differences

[V1]

What are the main differences between a regular gasoline engine and one that allows E85?

I notice many cars with the green leaf logo these days, but I don't know of any E85 stations in my area. Does it even make any sense to own a flex fuel approved vehicle if you're never going to use E85?

 

[simple_gifts]

Ethanol is corrosive, so fuel system components need to be designed to take it; this is what I have read.

There are no E85 public stations in CT, but plenty of FF cars. There is a requirement for the mfgs (i believe) to sell a certain % of FF cars, so for the sake of the team.....

 

[hisilver]

From what I gather the fuel system is made of components able to resist corrosion from the elevated percentage of ethanol. Along with computer stuff Im sure others will chime in on.

 

[Trav]

Good explanation.

http://en.wikipedia.org/wiki/E85_in_standard_engines

 

[wapacz]

other than compatible materials. You need bigger injectors since you need to be able to squirt more fuel in. Then some way to tell how much ethanol is in the mix. The system gm uses activates when the car has been fuel and I believe uses the O2 sensor to figure out how much ethanol there is in the tank of gas.

 

[wapacz]

Originally Posted By: simple_gifts
Ethanol is corrosive, so fuel system components need to be designed to take it; this is what I have read.

There are no E85 public stations in CT, but plenty of FF cars. There is a requirement for the mfgs (i believe) to sell a certain % of FF cars, so for the sake of the team.....


From my understanding they get some kind of CAFE multiplier on flex flue sold vehicle. Which helps them meet the cafe standards.

 

[UNC017]

Originally Posted By: wapacz
other than compatible materials. You need bigger injectors since you need to be able to squirt more fuel in. Then some way to tell how much ethanol is in the mix. The system gm uses activates when the car has been fuel and I believe uses the O2 sensor to figure out how much ethanol there is in the tank of gas.


The first Chrysler systems (back in the 90s) had a little module in the fuel supply line that used an LED laser to measure the refractive index of the fuel as it passed through. That data was fed to the PCM look-up tables. That way the PCM could work with any percentage ethanol from 0 up to at least 85% (E85), and could react instantly to slugs of poorly-mixed gasoline and alcohol right after a re-fueling. Not sure if that's still the case or not, but I'm fairly certain there's more to it than just reading the O2 sensor.

 

[boxcartommie22]

all ford vehicles made after 1999 they are made to use e19 ethanol....

 

[Spazdog]

Originally Posted By: boxcartommie22
all ford vehicles made after 1999 they are made to use e19 ethanol....


The Duratec may tolerate ethanol, but it definitely runs better on gasoline with just gasoline in it.

...then again my Duratec probably does not have Ford fuel management. It's definitely got a different 'Denso style MAF.