Thursday, January 15, 2009

Save Money With Mid-Grade Gasoline

Miles Per Dollar

I remember back in 1986 when I bought my first new car. It was a 1986 Honda Accord. The price of gasoline was around $1.15 for regular and $1.25 for mid-grade. I had an idea for saving money on gasoline by measuring "Miles Per Dollar" instead of the usual "Miles Per Gallon".

Through my own simple research what I found out is - and I can only work with figures I calculated with my own cars - I save about $400.00 per year by filling my cars with mid-grade instead of regular (CHEAP) gasoline.

Here are the numbers: With regular gas, my 1986 Accord (and now a 1998 Civic with similar results) got, on average, about 29 Miles Per Gallon (MPG). With mid-grade gas, my car gets an average of 34 MPG. That's 5 more miles per gallon for every gallon of mid-grade I purchase over the cost of regular. Or, to look at it another way: For every 6 gallons of mid-grade gas I buy, I get 30 extra miles of fuel efficiency over regular gas for an up-charge of only $0.60. 10 cents more per gallon for mid-grade. That's like getting a 60 Cent gallon of gas for every 6 gallon of mid-grade that I buy!

As far back as I can remember mid-grade gasoline has always been 10 cents more than regular. Even at today's prices ($3.35 per gallon in Chicago) mid-grade is still only 10 cents more per gallon than regular.

So, here is another way to look at it in real dollars:
6 gallons of regular gas costs 6x$3.25=$19.50.
6 gallons of mid - grade costs 6x$3.35=$20.10.
Still only 60 cents more. But for that extra 60 cents you get 30 more miles of fuel efficiency which is equal to $3.25 (one gallon) of savings for every 6 gallons you buy.
Or, how about $6.50 savings per fill-up! (12 gallon tank)

How many times do you gas up every year? 60 times? More? I commute about 90 miles per day 5 or 6 days a week. Sometimes I'm gassing up every 3 days. And keep in mind, these numbers are for a fuel efficient car. I wonder what kind of MPG some of you are getting with your SUV, VAN or pickup.

Measure The Difference

For those of you who are not familiar with calculating MPG here is how it is done:

Fill your tank (to the top) with regular gas and make sure you zero your trip odometer. Your vehicle is now ready for testing. Drive around as you normally do and a few days later, when you return to the gas station, you will begin logging data. When you are ready to fill-up, write down how many miles are shown on the trip odometer. This time fill your tank with mid-grade gas and write down how many gallons of gas you put in your tank. Keep these numbers together.
Zero your trip odometer again. Drive for a few days until you need gas. When you are ready to fill-up, write down the miles you see on the trip odometer, fill the tank and write down how many gallons you put in the tank. Keep these 2 numbers together.

You now have the basic data for calculating MPG for regular vs mid-grade gasoline. Divide your first odometer reading by the amount of gas you put in your tank (example 288 miles divided by 9.78 gallons of gas = 29.45 MPG). This is your MPG for regular gasoline. Do the same with the second set of numbers (example 312 miles divided by 9.23 gallons = 33.8 MPG) and you will have your MPG for mid-grade gasoline. In this example the difference between the two MPG numbers (4.35) demonstrates how much more efficient mid-grade gas is than regular gas.

Fine Tuning The Numbers

Of course, if you want more accurate data you should run the test twice with each grade of gasoline. You should run the gas tank as far down to empty as possible without running out before each fill-up. This will prevent the two different grades of gas from mixing together, spoiling the test results.

It is important to be very consistent in your driving habits during the testing period. For example, if you use your air conditioner during most of the regular gas test but not in the mid-grade gas test your results will be too inaccurate for comparison. Local driving vs freeway driving or a few long evenings with the engine idling at lovers lane will also spoil the test results. You could wait to take your measurements on a long road trip. 2000 miles of Interstate Highway make a perfect test track for MPG comparison.

Green Peace

For any of you who are concerned about the health of our planet, you could look at not only the waste of money but also the waste of fuel we are pumping into our atmosphere. For every 6 gallons of regular (CHEAP) gasoline you put in your car, one of those gallons is wasted. Up in smoke! As a rough calculation, my car would pump 127 gallons of wasted fuel and carbons into the atmosphere every year if I were to use regular gasoline.

I think the Oil Industry is laughing all the way to the bank. You think you are saving money by buying the lower priced fuel when, in fact, you are actually spending more by a rate of about $3.25 per 6 gallons.
The way I see it:
"I have to buy Mid-Grade. I can't afford to waste good money on Cheap Gas".

Show Me Your Results

If you try the MPG test on your vehicle, email me your results. I would like to know what kind of savings you get on your SUV, VAN, truck or luxury car. If the data is useful, I will average all of the new test scores and post these numbers in this article.

Click the link "ASK QUESTIONS. EMAIL STEVE" to send me your information or to ask a question about this article. Thanks!

1 comment:

wgpeters said...

A long time ago, I tried your experiment, and saw no benefit to buying mid grade gas. However, that was before computerized engine controls that monitor and control spark and combustion. Based on your comments, I believe I will try the experiment again with my Ford Escape Hybrid.