It's skeptics like you who help prevent alternatives from coming to market due to misinformation. Sure mileage will drop if you just up and switch from gasoline to E85. However, if an engine is built to use E85, there isn't that mileage or power drop. Improvement in combustion efficiency can more than overcome the lower heating value of E85 compared to gasoline. Ethanol doesn't ruin your engine, but can destroy seals that aren't compatible with alcohol. We aren't supposed to talk about politics, but I am far from being a lefty yet I support alternative fuels.

 

Tom, I'm not sure where I fall on the political spectrum. My right wing friends think of me as a 'Lefty', my left wing friends think of me as overly conservative NUT JOB. The left/right bit doesn't seem adequate to describe ones political thoughts. Politics does seem to have an extraordinary effect upon transportation fuels, and the policys that regulate them. But we really aren't supposed to get into plitical discussions on this board, so leaving all politics aside, the homework has already been done. Ethanol, even long term use, doesn't not ruin or harm your engine in any way. Engines run on ethanol wear out less rapidly than gasoline only engines. Most of the increased engine life is due to the fact that ethanol burns about 200*F cooler than gasoline. Are you using E85 or gasoline with 10% ethanol as an oxygenate ? What exactly do you mean by 'ethanol season'? You are right that ethanol has about 75% of the BTUs of gasoline, but what does that matter ? Ethanol burns in your engine with a thermal effificiency of 40%, gasoline usually only manages 25% or so, thus negating gasoline's BTU advantage. If you have a car that loses half or more of its MPGs with an ethanol blend, something is wrong with your car. My suspicion is that your oxygen sensor doesn't know what to do when it reads the extra oxygen in the exhaust and thinks the engine is running lean. So it squirts as much fuel as it can, to try to correct what it mistakenly believes is an overly lean condition. Ethanol is really wonderful stuff, but it isn't quite as simple as pour it in and go. Most of us still have engines setup for gasoline, the setup and tune is differant for ethanol. DF

 

E85 has high octane, 100 - 105 octane rating.

If you design a motor to take advantage of it, you can make a lot of power (higher compression or boost). But you'll have to burn more, because ethanol's energy density is lower than gasoline, as already noted.

I'm pretty sure that flex-fuel vehicles from the factory don't take advantage of the high octane rating, since they also need to seemlessly burn regular gasoline.

 

****, I think you and Tom are misunderstanding how this works. Yes, ethanol has less BTUs per gallon than gasoline. But fuel economy is NOT dependant upon energy density. Think of it this way....a gallon sized chunk of oak has more than 10 times the energy density as gasoline. But because it burns so slowly, you can't run it in your car. The BTU thing measures how much fuel it takes to raise a gallon of water 1 degree. But we aren't trying to boil water in our engines. Ethanol has a faster flame speed than gasoline, .43 mps, as opposed to gasoline's .34. That means that more of the burn can be utilized to push a piston instead of going out the tailpipe as waste heat. AND alcohol's higher octane will allow you to raise the compression for still more economy. So, no, you don't need more of it. What you need is an engine with enough compression to be able to take advantage of ethanol's better burning properties. DF

 

Hmmm... even the ethanol folks concede MPG is affected.
Apparently, there is a degradation in MPG according to the Ethanol sites below, but the decrease in MPG is much less than I had thought for the blends. E85 is a bit more of a difference.

www.ethanol.org
Because the cost of ethanol was lower than the cost of gasoline, although MPG of ethanol blends were slightly lower, cost per mile of operation was generally lower when using ethanol blends.

http://www.drivingethanol.org/aspx/why_ethanol/faq.aspx
For a 10% blend:
While there are many variables that affect fuel economy (weather, car condition, road grade, tire pressure, air conditioner use, etc.), studies indicate that fuel economy with ethanol-enriched fuels may decrease by about 2 percent in fuel-injected cars. So cars that average 30 MPG on the highway would average about 29.4 with ethanol-enriched fuel. This is only a slight variance that probably won’t be noticed by the average driver.

http://www.greencarcongress.com/2005...udy_ethan.html
Using a 2001 Taurus test vehicle on a highway test loop:
Gasoline: 21 mpg
E85: 16 mpg

 

But did that taurus' computer advance the timing to take advantage of the E85's high compression ratio? I don't know that it does.

Also, i belive what dino is trying to say is that an engine designed specifically to run on E85 would have a higher compression ratio and advanced timing to take advantage of it, making it more efficient.. right?

 

I don't know if the timing advances.

But your second point, there's no argument there. So long as the engine is designed to take advantage of the higher octane, it'll work well. Advancing ignition works to a small extent. Raising compression ratio would work to a much larger extent, as would upping boost on a turbo application. There's no practical way to change compression ratio on the fly, though.

Saab has a flex-fuel turbo car that CAN take advantage of E85's octane. They claim a 20% inccrase in output, as boost is increased (it's a turbo engine). Quite nice... I'd do the same with my blower - up the boost - if I had a source of E85 around my house.

 

Can a older truck with a 460 run it and what changes need to be made to run properly?

 

Rebel no an older carberated truck cannot run E85, but running 10% blended ethonal is ok. A test was done by someone on another forum to see at what point the rubber starts to degrade and it was in the neighbor hood of 25% blend before the ethonal started to attack the rubber seals.
On your truck you would hve to change your entire fuel system including tank, pump, lines carb (you would need a alky rated carb) fuel mixture settings and timing would also have to be tuned for use with it.

edit But anyone that is losing 50% of thier mileage switching to 10% ethonal is either lying which I don't want to believe anyone on here would do or has major serious problems with thier vehicle that really needs to be addressed. Most likely a sensor problem that has put the computor in drive home mode and isn't making any corrections.

 

Interesting.. maybe we'll find a turbo on that new 3.5 v6 ford is putting out in the future with the ability to up the boost on ethanol, that would be prety cool.

 

Go to the "pure alcohol" sub category under this alternitive fuels category and check out what's going on. Just remember-the Model T was designed to run on gas or alcohol-it had a steel tank, copper fuel line, cast iron carb, so Henry knew 100 years ago that we could beat the Cartel!!!!!!

 

I just bought an '06 F150 Lariat with the 5.4L Triton FFV. I did a heck of a lot of research on E85. I also hunt pheasants in SD every year on private land, and the family that we hunt with knows quite a bit about E85. Here is what I understand:
1) Only vehicles with engines (and hoses, gasquets, etc) designed to handle the ethanol can use E85
2) Ford's FFV engine has a sensor that allows the engine to understand the relative level of gasoline versus ethanol in the mix to regulate and operate accordingly
3) E85 will result in lower MPG, and in the past it was as much as 35%-40% lower MPG... Today's engines that are equiped with sensors to allow the engine to adjust are quoted as only taking a 10-15% hit to the MPG (I will validate in SD this fall when I can get a tank full of E85)
4) Financials - except right after hurricane Katrina, when there was unusually high demand for ethanol, E85 seems to be lower cost than gasoline (part of this is due to a subsidy to fuel producers and retailers to encourage non-gasoline fuels) - if your discount on the cost of the gas per gallon is greater than the loss of MPG, then E85 makes sense for the truck owner (although total cost is really unknown given the subsidies paid out of our tax dollars)
5) Production - once only produced from corn (which brought up an eithical dilemna - use corn to feed the world or make gas?), there are now refineries that can run on lots of renewable agriculture products, including agriculture waste. It seems to be true that the amount of energy required to produce E85 is higher in relation to the amount of energy E85 produces than the same ratio with gasoline, but this seems to be improving as refining processes get better/smarter/more efficient - thus the gov't subsidies

This is a summary from all of the websites and magazine articles I have read, as well as the information from friends in E85 country (mid-west) - by no means gospel, but some data anyhow.