The Truth About Gasohol

I'm sure these gas prices have gotten to you no matter where you are or how much you drive. Here gas prices are at $3.50/gallon for regular and steadily rising. While not as high as some other places in the country, I like many other Americans, am feeling the pinch. Now, before you start blasting me for driving a huge SUV or truck that gets 10 miles to the gallon, I drive a Toyota 2 wheel drive truck and I have a motorcycle that gets 50 mpg. Now with that settled I am going to give you a little info into getting what you pay for.

Many people have wondered why does one station have gas at a lower price than a station that is across the intersection. Many times the answer is ethanol being added to the gasoline so that the price is lower. Now, this is not always the case, but many times it is. Stations that have ethanol added will have it displayed somewhere on the pump that the gasoline contains "up to 10% ethanol." This is to let you know that you are helping the environment, I mean who hasn't heard about ethanol right.

Don't get me wrong, ethanol is a great idea and in time will be a viable fuel source. Right now, ethanol is made just like moonshine. It is a process called distillation. Distillation requires large amounts of heat to boil ethanol out of corn "mash". Can you guess where the majority of that heat comes from? That's right, oil, natural gas, and other fossil fuel sources. There are many figures that say that 1 "gallon equivalent" of gasoline equals approximately 1.3 gallons of ethanol which is great now we have more for our money.

Now to gasohol (which is gasoline that contains 10% ethanol) or the cheaper gas that we all line up for. I did a study on my own daily driver when gasohol was 3.29/gal and gasoline was 3.39/gal. Just looking at the numbers we see that the gasohol is cheaper. I kept all the variables the same, I drove my same daily route, put the same amount of fuel in the tank, and I checked the mileage at the first station I came to when my low fuel light came on. And just for you pessimists, I was on fairly level ground both times, so the fuel hadn't shifted in the tank to cause the light to come on. This is what I found.

With gasohol (the cheap stuff) I got 16.6667 miles per gallon, and with gasoline I got 18.75 miles per gallon. This is a little better than 2 miles per gallon better fuel mileage. Let's do the math and see who's cheaper.

Efficiency of gasohol vs. gasoline = 89% (16.6667 divided by 18.75)

In case you're savvy, you probably noticed that we got 30% more ethanol for burning a gallon of oil, and you would be correct. The problem is that gasohol is only 10% ethanol which means you only get 3% more per gallon when it goes into your tank. This 3% increase is offset when you realize that the gasohol is 11% less efficient leaving you with a net of -8%.

Gasohol

3.29 divided by 16.6667 = 19.7 cents per mile

Gasoline

3.39 divided by 18.75 = 18.08 cents per mile

As you can see it actually pays to pay more at the pump in the long run. 1.62 cents per mile to be exact. Doesn't sound like a lot, but if you drive 300 miles, you've just saved $4.86.

Now many will say that the reason to burn ethanol is so that we burn a cleaner fuel. That is true, ethanol is a cleaner burning fuel than gasoline. Remember that gallon equivalent thing that we used to make the ethanol? That's right, we burned a gallon of oil already to make the ethanol, either way the oil gets used in one way or the other. Now we've burnt a gallon of oil and a gallon of ethanol on top of that (and got less mileage). Ethanol would have to be 100% clean for this to help the environment.

That said, we need to find alternative sources of energy. Ethanol is a great candidate, we just either have to find another way to make it i.e. solar heating, or we need to tackle this problem from another angle. Maybe we need to focus on cleaner electricity production like nuclear or solar. I don't know the answer, but I know that I'm using more fuel by burning gasohol than I am when I use gasoline, and it costs me more.

Notes:

All tests were done in a 2003 Toyota Tacoma, at the same speed, and on the same road. Your results may not duplicate those found here.
This test was for gasohol (10% ethanol) and not E85.