Analysis: Gas mileage going down?

Bill Gephardt is a consumer advocate, founder and operator of Get Gephardt Approved Dot Com, and St. George News columnist. The opinions stated in this article are his and not those of St. George News.

ANALYSIS – Just what is going on with that nice fuel-efficient car you bought a few years ago?

That’s the same question I’ve been asking. I bought a shiny new Toyota Prius about five years ago, and back then it got about 50 miles per gallon. The record for a tankful of gas was 56 miles per gallon. The lowest mileage was 42 miles per gallon, but that was when I was driving 80 miles per hour through the “test areas” of the I-15 interstate between Salt Lake City and St. George.

Now, everything has changed.  The best I can do anymore for a tankful of gas is about 45 miles per gallon.  And, on those “test areas” of the freeway, I’m down to sometimes 34 miles per gallon.

I went and asked a few mechanics if they might know what is causing this precipitous decline in my gas mileage.  They didn’t know.  One guy said let’s check the air in your tires (the pressure was just fine).  Another guy said it’s because the car is getting old, and maybe it needs a tune-up (that wasn’t it).  A third said my driving habits must have changed (what? Maybe he thinks I hold the doors wide open and ride the brakes!!).

Nope, it was none of that. It was a problem that I found many mechanics don’t even know about: ethanol.

Ethanol is now being added to gasoline at rates of 10 to 15 percent. That, according to an article in “Popular Mechanics,” will decrease fuel economy 20 to 30 percent.

Ethanol, say numerous published reports, has significantly less energy content than gasoline. That means when ethanol is mixed with gasoline, the mixture will have less energy content than pure gasoline.

And that explains why, in my Toyota Prius, I am now getting I would guess a little more than a 15 percent decrease in my fuel economy.

Do you still want to try to purchase pure gasoline? You can, but it’s about as plentiful as panning for gold in the Great Salt Lake! I found “Craig’s Service Center” in Salt Lake has pure gasoline.

“It’s brought in to me from Las Vegas,” Craig told me.  “It’s getting harder and harder to get. But people who want the mileage, or people  who have special cars, don’t mind paying the 20 cents more per gallon.”

In all, I only found seven gas stations in all of Utah which offer ethanol-free fuel, and only one in St. George from a website called PURE-GAS.ORG.

So, go tell your mechanic you now know why you’re getting worse gasoline mileage than ever before:  ethanol in the gasoline.

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Copyright 2012 St. George News.

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  • Mike April 13, 2012 at 8:32 am

    So the question here is… why are they putting so much Ethanol into the fuel? It sounds like cutting or diluting to me. Does this practice increase or decrease their profits?

  • Jeff April 13, 2012 at 9:28 am

    Using E85 instead of straight gasoline results in 20-25% lower fuel mileage.
    Gas with 10% ethanol only changes mileage by 3-5%.
    Find yourself a better auto mechanic.

  • ChiefMechanic April 13, 2012 at 5:05 pm

    to Mike: Ethanol is added to gasoline as an oxygenate agent– It makes the gasoline burn cleaner. Gasoline with 10% ethanol is mandatory in places like New York to cut down on smog formation.

  • Bobby Fontaine April 14, 2012 at 5:50 am

    many have opinions, few understand facts, but that is only because there are so many lies with so little truth

  • tyler April 14, 2012 at 10:30 am

    just got a tune up, the mileage still sucks, 10 bucks barely put my needle above E in my 2000 mitsubishi galant and prices are expected to get worse?? lord have mercy!!! wish we had reliable public transportation to cover all areas of the city, i’d park the car!

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