Flex Fuel users what do you think and a couple questions

[JacoLesFlea]

I have been driving a 2009 Impala E85 compatible while my car is in the shop. I filled it with e85 @ 2.14 a gallon compared to 2.79 a gal for 87 octane. I have herad you lose a couple miles a gallon, but you save quite a bit at the pump. I have had the car going on two weeks and topped it off at the pump with e85.... I only know of the one station that has e85 fuel if I put in 87 octane when I have e85 in it would I hurt the engine? or can you mix the fuels...I have the car intill Friday so I am curious.

[hover]

e85 was engineered to be compatible, as it's already 15-20% gasoline from the pump. You'll be just fine. Really no sense in designing an engine that potentially *inflexible* if there's not enough infrastructure to support it.

[hbarcat]

You'll likely lose at least 30% fuel economy using E85 compared to regular gasoline.

gasoline A/F ratio = 14.5 to 1
alcohol A/F ratio = 8 to 1

[Pilgrim]

E85 is less energy dense and therefore mileage is considerably less, as Hbarcat noted.

E85's ethanol will also eat and eventually destroy components in older cars' fuel systems. NOT for use in cars which are not specifically designed for it.

[hbarcat]

Flex fuel vehicles have a sensor that tells the computer what fuel you have in the tank so the engine knows what A/F ratio to use no matter what ratio of gasoline to alcohol is present.




Even though alcohol is less energy dense than gasoline, you could still get close to the same fuel economy using it by having an engine with a higher compression ratio since alcohol is inherently more tolerant of high ratios.

Unfortunately, flex fuel vehicles must be able to burn pure gasoline as well as alcohol and so they are limited to a lower compression ratio (meaning the advantage of alcohol is wasted).

[Mike N]

Alcohol is for drinking.

[JacoLesFlea]

Originally Posted by hbarcat

Flex fuel vehicles have a sensor that tells the computer what fuel you have in the tank so the engine knows what A/F ratio to use no matter what ratio of gasoline to alcohol is present.




Even though alcohol is less energy dense than gasoline, you could still get close to the same fuel economy using it by having an engine with a higher compression ratio since alcohol is inherently more tolerant of high ratios.

Unfortunately, flex fuel vehicles must be able to burn pure gasoline as well as alcohol and so they are limited to a lower compression ratio (meaning the advantage of alcohol is wasted).

Thanks filled the tank and went thru the wash I am returning it this morning to the dealer and picking up my baby..to put back in the garage... The Impala is a very comfortable car and not bad pickup either.

[Nightlyraider]

If you look at the actual molecular carbon chain in each fuel; there is nearly twice as much stored energy in a gallon of gasoline as there is in ethanol. Depending on the gas/alcohol ratio (varies quite a bit depending on locale, Minnesota has alot more alcohol, our corn is cheap) you will get varying fuel efficiencies.

E85 cars in their current state do not equal Gasoline powered cars in terms of power efficiency.