Alcohol (let's talk pure ethanol here) has a lower caloric content than, say, gasoline, which only means that a given weight of fuel produces less calories. So presumably if you fill up your Ford Expedition with ethanol, you'll get 5 mpg instead of 7 mpg.

However, alcohol has some up sides to it that gasoline can't easily compete with:

Higher Performance. Alcohol is about 150 octane or so -- nearly twice as knock-resistant as gasoline (~87-90 octane.) That means you can engineer engines differently: think about an alcohol engine running at a compression ratio of 18-20:1, or lots of boost Higher compression ratios buy you higher efficiencies: one of the reasons diesel engines are more fuel-efficient than gasoline engines. That's why race cars tend to use alcohol and other alternative fuels. This is the big win, where the engineers can make up for the lower caloric content.

Passing Emissions. Alcohol burns much more cleanly than gasoline. NOx, HC and CO emissions are far lower. Most of what you get from burning alcohol is CO2 and water. BTW if you convert you vehicle to run on alcohol it qualifies under the alternative fuel law. Which lets you get rid of most of the equipment, which since it's cleaner burning in the first place you don't need anyways.
California HotRods run alcohol so they can run the fancy blowers & such.

Because alcohol burns so clean, maintenance costs are much lower for an engine burning alcohol than for the same engine burning gasoline. Engine life should be longer as well. This is actually something of a problem for alcohol conversions -- alcohol's solvent effect tends to dissolve old varnish, gum, filth and dirt in existing engines converted to gasoline and loosen things up.

Alcohol's Down Sides

You knew there had to be some, right? They are mostly minor.

Cold starts are more difficult. Alcohol doesn't vaporize quite as easily as gasoline, so cold starts are more difficult. Some sort of preheater (glow plugs?) would be handy.

Corrosive. Alcohol is corrosive to some metals as well as synthetic rubbers. The fuel system needs to be nylon or other alcohol resistant plastic. You also might want to due what CART & IRL teams do, "pickle" the engine. This involves running gasoline through it, after the cars come off the track.

Conversion of an existing engine to alcohol is pretty straight forward job. The fuel system needs to be made alcohol resistant. If carburated, the jets need to be bigger. If it's a slightly more modern engine, the fuel-injection system probably needs to be reprogrammed (and possibly different injectors.)

Why we haven't converted to alcohol? That's a very good question, don't you think?

President Carter was pushing for that 25 years ago. Conversion would accomplish at least three good things: (1) we stop being dependent on a foreign-controlled resource and (2) we support family farmers -- the very people for whom politicians love to trumpet concern about at election time -- and (3) we cut air pollution. A lot. Item number one, of course, has huge implications for national security and foreign policy. The other two are slightly more prosaic, but they have other side effects affecting public health and the way we develop this country in which we live.

Our failure to convert couldn't possible have anything to do with the amount of money contributed by the oil companies to politicians of all stripes, could it? See the oil company lackeys currently in office for details.

 

Most octane boosters are nothing more than wood alcohol.
Other than it being corrosive and a little less stable than gas, you can run it.
An old Grand National trick we used to use was setting up an extra injector run to a seperate fuel cell with alcohol. When it hit a certain boost, the alcohol injector would come on. If I remember correctly, we were running around 30 PSI on pump gas and the alcohol injector. Not bad eh?!?! ;)

 

Didn't Chevy actually ship Corvairs from the factory with that option???

 

I've thought about this a little myself, but I think the downside is a little more than you think. A friend of mine had a 68 ProStreet vette with big block running alcohol. He converted it back to gas. The minuses he encountered were that Alcohol is $4-6 a gallon unless you buy it buy the drum, and then it's still over $2. Also, the mileage difference is more like 10mpg to 1mpg instead of 7 to 5. Although with today's technology with efi and a little redesign of the engine you could probably bring this up a little. The other problem is that it doesn't store for very long without collecting water.

Interesting idea though...

 

Cars in south american countries run on alcohol. I remember the car had trouble starting when it got down to 50 degrees.

 

No they're not. Most octane boosters are some mixture of toluene, xylene, and some other stuff, which are petroleum products. Xylene is 114 octane and toluene is 117.



[Modified by VetteGS, 4:19 PM 10/11/2001]

 

Get this month's "Car and Driver".

Brock Yates' column is all about the cons of ethanol.

I'm all in favor of it - logically, I understand the sheer stupid short-sightedness of running around on a depletable resource - but ethanol isn't cost-effective yet. It takes more energy to produce a gallon of ethanol than the gallon of ethanol can return to you in its combustion. It's the same story currently with H2 hydrogen.

Oh, yeah, I forgot...it's hydrophilic too. Mixes easily with water / absorbs water out of the air. Harder to store and transport for any length of time - get a tank, burn it off quick! :D

In about 5-600 years, maybe...

~Matt


[Modified by Matt Black, 7:35 PM 10/11/2001]

 

I run my race stuff on alcohol, methanol alcohol!
One gallon every hundred feet!
I use an Enderle injector on one engine and a Hillborn on the other.
They both make a mess out of the oil, lot's of moisture gets in it. They can be a real bitch to start, I use a gasoline primer. But using 17 to 18 to 1 compression is nice. The 572 runs 36 degrees of total timing ang the little 427 I run 46. Try that on gas! Alcohol eats the daylight out of everything, between events I have to completly drain everything, blow it dry and fill everything with ATF, just to keep it all from corroding away. And it still seems to. I will stick with gasoline for the street.

 

there is one more downside to running alcohol... formaldahyde. bad news. bigtime.

At Long Beach, the CART guys have to get out of the tunnel within 30 seconds, or they will pass out. not good at all.

alcohol is a viable fuel, except the entire system needs to be converted. In the midwest, they are using M85. 85% methonal and 15% gas. Gives it colour, smell and flame if it catches fire. Also, there is enough gas to slow the corrosive effects.

 

Filler-Up with Johnny Walker Blue... only the finest for my car.. :)

 

I need to find a way of combing these thread ...

Anyways, there's talk in the Engine Mods section.

Seems to be good for those with high boost and concerns about the sniffer test