Ethanol (E85) in Production Cars

[shiny side up!]

Hello,

Not exactly racing specific, but I have a question that I thought someone on here might be able to help me out with re: road-going cars that can run both gasoline and an 85% ethanol / 15% gasoline mix (E85 here in the States).

All of the auto manufacturers here have at least a few models that they offer as "FlexFuel" - meaning they can run on gasoline or E85. All of these manufacturers also state that you get "the same engine performance" whichever fuel you are using. I interpret "the same engine performance" to mean similar responsiveness and power.

Now, a gallon of E85 contains roughly 70% of the energy that a gallon of gasoline does. It also has a higher octane rating (~100-105) than regular gasoline (87-91 over here). The auto manufacturers tell you to expect about 30% worse fuel economy (miles per gallon of fuel) using E85 due to its energy deficit.

Now, here's my question (sorry it took so long!) - the increased octane rating in the E85 should allow a leaner fuel mixture, right? Or more advanced timing? And if you were to actually run E85 at a leaner AFR, or more advanced timing, shouldn't that make the combustion process more efficient, and therefore the fuel mileage look a little better than it otherwise would?

Basically, I just don't remember my combustion and engine calibration courses well enough to answer my own question, I guess... but it seems to me that with a roughly 15% higher octane rating, we should see some sort of benefit... and if the mileage hit running E85 vs. gasoline is right in line (-30%) with the energy densities of the two materials, then we aren't seeing any benefit from that increased octane rating.

Thanks for any help or insight you may be able to provide!

[AU N EGL]

The increased octane is to prevent premature detination of the fuel.

I think I saw some place that the 30% poorer fuel milage was optimistic. more like 40-45% less fuel milage.

The cost of E-85 is not 40 or even 30% less then petrol, plus with only 1500 or so fuel stations that sell E85 across the US. Then you get into the engine damage, especailly the valve train of engines using E85. Plus the high cost of corn to produce E85, which takes corn out of the food supply for animal feed, causing food prices to skyrocket. Is it really worth using E85 at all??

Manufactures are finding that vehicals with Flex fuel usage are sitting in lots and not selling. Not to mention the hybred cars are also not selling so several manufactures have outrigt canceled production of hybrid modles.

Consumers just dont want E85 or hybrid vehicals, nor governments telling them what they must and can not have.

[shiny side up!]

Originally Posted by AU N EGL

The increased octane is to prevent premature detination of the fuel.

I figured this would allow a leaner AFR or more advance, no?

Originally Posted by AU N EGL

I think I saw some place that the 30% poorer fuel milage was optimistic. more like 40-45% less fuel milage.

My new truck is FlexFuel, so I will test this out soon enough and have some actual data to use. I have seen reports concluding from 25-35% reduction, I hadn't yet seen anything as extreme as 40-45%... but that may indeed be what I find!

Originally Posted by AU N EGL

The cost of E-85 is not 40 or even 30% less then petrol, plus with only 1500 or so fuel stations that sell E85 across the US. Then you get into the engine damage, especailly the valve train of engines using E85. Plus the high cost of corn to produce E85, which takes corn out of the food supply for animal feed, causing food prices to skyrocket. Is it really worth using E85 at all??

I agree, I live in Michigan where there are actually a hundred or so refueling points for E85, and it is generally about 15-20% cheaper than regular unleaded. I am also concerned about the fact that by the time you grow the corn, transport it to a refinery, make ethanol, truck it to a storage/mixing facility, and then transport it to a gas station, the net energy used to create the ethanol at best is a break-even situation. If, however, I was convinced sometime in the future that the energy balance works in E85's favor and the net pollution produced through this entire supply chain to my tailpipe was lower by my choosing E85, I would eat the price difference at the pump for the piece of mind. It wouldn't change the world, but I would at least be using the greenest alternative at my gasoline-chugging disposal!

Originally Posted by AU N EGL

Manufactures are finding that vehicals with Flex fuel usage are sitting in lots and not selling. Not to mention the hybred cars are also not selling so several manufactures have outrigt canceled production of hybrid modles.

Consumers just dont want E85 or hybrid vehicals, nor governments telling them what they must and can not have.

The sticker price for my vehicle was the same as the same one sitting next to it without Flex Fuel capability. Supposedly it cost GM about $400 more to make a Flex Fuel model, but they don't pass that cost on to their consumers due to CAFE regulations or some such bologna. Anyway, since I was buying a vehicle that I anticipate owning 5+ years, the flex fuel was actually something I bought purposefully in case the manufacturing technology and supply chain mature enough over that time period to make ethanol a worthwhile option. I'm certainly not convinced it is today, but I will run a tankfull or two just to try it out until then...

[Chris Y]

Sorry, not really racing related, so moved to the Road Car forum.

[graham bahr]

apparently E85 is BIG business in sweden and lots are racing on it over there, you will burn more of it but will actually gain 10-15% in power, but to run it you will need completly different jet settings in your carbs or map in your ecu

[Leighton Irwin]

Running 100% methanol was approx. 50% bigger jets.