Wisconsin Tops Minnesota

This is a guest entry from Gary Dikkers who explains that Minnesota and Wisconsin are near twins, except in the category of fuel economy.


One of my cars is a 1999 GMC Sonoma light pickup truck. Since I got my first driver’s license, I’ve always kept track of miles driven, fuel used, and computed my fuel mileage.

About four years ago I started to notice that whenever I put E10 in my Sonoma my mileage dropped. So I started doing tests — deliberately running the fuel tank to near empty, then filling up with either E10 or straight gasoline, and comparing results.

My Experience Using E10

Time after time, I have arrived at consistently similar results: When I burn E10, I get about 29 mpg at steady highway speeds, and when I burn straight gasoline, I get about 32 mpg.

That three miles per gallon doesn’t sound like much of difference does it? But let’s try a little thought experiment and imagine a theoretical trip of 320 miles.

  • If I use gasoline I would burn 10 gallons.
  • If I use E10 I would burn 11 gallons of that fuel.

But 90% of that 11 gallons of E10 would be gasoline. And what is 90% of 11? A: 9.9 gallons.

That means whether I burn gasoline or E10, I would burn almost exactly the same amount of gasoline on that theoretical trip.


When I use E10 in my Sonoma, I save virtually no gasoline, but I do have to buy 11 gallons of fuel. I now buy E10 only when I need fuel and have no other choice.

Is my truck an anomaly?

I admit my experiments are not scientific. Perhaps my truck is an anomaly, or there is something about the way I drive that causes the difference.

USDOT Statistics

That’s why I found it gratifying when I found a dataset that validates my experience.

Three years ago I discovered that the US Department of Transportation (USDOT), Federal Highway Administration (FHWA) keeps statistics of the amount of fuel burned and miles driven in each of the 50 states.

I live in Wisconsin and happened to know that Minnesota has had mandated ethanol in all their gasoline for the last ten years, while Wisconsin doesn’t. Two very similar states with one known difference — in Minnesota all motor fuels except diesel must be blended to at least E10.

So why not compare the average fuel mileage of the two states? I did, and what was the result?


In 2005 (the latest year for which data is available) Minnesota drivers drove 56.570 billion miles using 2.744 billion gallons of fuel. Their average fuel mileage was 20.62 mpg.

In that same year, Wisconsin drivers drove 60.399 billion miles using 2.592 billion gallons of fuel for an average of 23.30 mpg.

Minnesota drivers actually drove less than their cheesehead neighbors, but used more fuel to do it.

Something caused Minnesota drivers to get almost 12% worse fuel mileage than their neighbors to the east. What could have that been?

Both states have almost identical topography, climate, demographics, and about the same mix of urban/rural driving. (In fact, Wisconsin has a slightly higher ratio of urban to rural miles driven.) The two states are about as close to being twins as any two states could be. (Not counting the Vikings/Packers difference of course.) Yet fuel economy in Minnesota is worse, and their drivers buy and burn more fuel than their neighbors.

The only obvious difference that jumps out is that Minnesota has mandated its drivers burn a blend of ethanol and gasoline — a fuel with a known lower energy density than gasoline.

The facts are pretty clear: The results of this huge sample size – the entire State of Minnesota – validated my individual experience.

18 thoughts on “Wisconsin Tops Minnesota”

  1. Pretty cool stats.

    Ethanol has much lower energy content than gasoline. Now, if the price for ethanol were that much lower it wouldn’t be a problem…

  2. Sure, except that according to these statistics, the ethanol in E-10 has effectively no energy content; i.e. it contributes nothing to the goal of propelling the car.

    I’m having a bit of a hard time imagining why/how that could be. It sounds like the ethanol is making the whole engine run off-spec enough to waste the energy in the ethanol. Is that possible? I have no idea.

  3. Shocking, but those declines seem more in line with typical E85 mpg vs gasoline than E10.

    They tell usthat we’ve been running 5.7% ethanol here in California. I been getting 48-52 mpg in my Prius, pretty much the national average.

    (We are due to get mandated E10 in a few years, so I hope there isn’t any performance ‘ledge’ between 5.7% and 10%!)

  4. Absolutely amazing.

    As GE says, one wonders why it would be.

    Now if someone could dumb down the message to something that could be understood inside the Beltway, that would be great.

  5. Speed limits in Wi/MN?

    Any comps on vehicle sizes? Granted, probably close, but maybe more farm vehicles in WI? No Twin Cities.

    A real comp would apples to apples, such as all Ford Focuses in WI vs. all Ford Focuses in MN.

    Still, I am beginning to wonder long and hard about corn-ethanol. Unless there are radical improvements in EROEI, it is looking like a boondoggle.

    Clearly, we would be better off radically increasing MPGs, and switching to PHEVs.

    However, farm state Senators want it.

  6. Robert, guest posts are a great idea but you need standards. At a bare minimum, contributors should link to their data. The numbers I found on the FHWA’s Highway Statistics 2005 report were close to Gary’s, but small differences tell me I’m not using his exact tables.

    It would also be useful if guest posts contained some critical thought. For example, how did the two states compare before Minnesota mandated E10 in 1997? The 1996 Highway Statistics tables show a similar trend. VMT divided by gasoline use gives 21.7 mpg for Wisconsin vs. only 18.9 mpg for Minnesota. Ethanol’s effect is so powerful it can even reach back in time and affect pre-mandate numbers!

    [NOTE: VMT / gasoline gallons is not the proper way to calculate statewide MPG as it does not properly account for diesel trucks and such. But it’s the closest I could come to duplicating Gary’s numbers without his original data source. A proper calculation would still show WI drivers averaging more miles per gallon than MN, but the actual MPG numbers would change.]

    A critical thinker might also wonder if other (perhaps more rigorous) studies exist. For example::

    – Obviously biased American Coalition for Ethanol study finds 1.5% MPG penalty with E10.

    – Old test with cold-weather data shows E10 actually improves MPG half the time.

    – Really old Indian test shows 1% MPG loss in city and 3.9% MPG loss on highway for E10.

  7. As much as I don’t like ethanol, I find it hard to believe that there could be this much difference. I did notice that I got slightly better mileage driving in Oklahoma (no ethanol) vs. Houston (reformlated E10).

    Could it be that the engine contol unit has some difficulty responding to the changing fuel mixture? The ECU may run the ethanol mixture too lean, not accounting for the O2 in the fuel.

  8. I live in Minnesota, 20 mi. from the Wisconsin border (Suburb of St. Paul). There are a couple of differences between the two states. Gary said that WI had a higher urban to rural ratio than MN. I don’t know how this is defined, but MN has the twin cities metro area which I believe is much larger and more conjested than anything in WI.

    Another difference is average income in MN is quite a bit higher than WI. It may be that higher income means bigger less efficient cars.

    I also have a flex fuel vehicle, and the difference I see between E10 and E85 is about 15%.

    Finally, I should point out that in my experience, the average Wisconsin driver consumes about a gallon of alcohol while drive 320 miles.

  9. Finally, I should point out that in my experience, the average Wisconsin driver consumes about a gallon of alcohol while drive 320 miles.

    What does that work out to? About 1 beer for every 30 miles.

    Dennis Moore, Dennis Moore, galloping through the sward, Dennis Moore, Dennis More and his horse Concorde. He steals from the rich, and gives to the poor, Mr Moore, Mr Moore, Mr Moore.

  10. What does that work out to? About 1 beer for every 30 miles.

    that’s just to chase down the whiskey.

    Thanks for revealing the inpiration for my energy blog pseudonym.

    He steals from the poor and gives to the rich, Stupid b****

    This re-distribution of wealth is harder than I thought

  11. doggydogworld said: “guest posts are a great idea but you need standards. At a bare minimum, contributors should link to their data.”


    You’re right. Here is where I got the data:

    2005 Motor Fuel Use

    2005 Vehicle Use

    Doggy said: A critical thinker might also wonder if other (perhaps more rigorous) studies exist.

    I agree, what I found isn’t rigorous — but it is interesting.

    I’ve only tracked this back to 2003 and 2004, and the data is similar for both years.

    2003 – MN = 20.25 mpg; WI = 23.20 mpg

    2004 – MN = 20.62 mpg; WI = 23.30 mpg

    I haven’t gone back to 1996 as you did. I’ll have to check on exactly when Minnesota first mandated E10.

    Reliability of the FHWA figures

    I also have some concern about how the FHWA collects their data. The figures on gallons of fuel consumed should be pretty accurate — I’m sure those come from fuel tax receipts. I’m not so trustworthy of the FHWA mileage driven figures, and would like to know more about how they gather those. They don’t have a way of reading and recording the odometer in every car in Minnesota and Wisconsin, so there has to be some statistical sampling, extrapolation, and estimating going on. I’d like to know more about exactly how they arrive at the mileage figures they publish.

    Possible reasons for Minnesota’s worse mileage

    When I first discovered this two years ago, I sent a letter to the Minnesota Governor’s office asking if they were aware of their statewide mileage figures? Never received a reply.

    But I did finally connect with a person in the Minnesota Dept of Agriculture who oversees the state’s ethanol promotion program. His theory was that the FHWA numbers couldn’t possibly be reliable, and that if there was any difference in mileage between Minnesota and Wisconsin, it had to be because it’s a “well known fact” that Minnesota drivers own a much higher percentage of SUVs than Wisconsin drivers. (I don’t know how he knew it was a “well known fact.”)

    I also discussed this with the American Lung Association of Minnesota who are strong advocates of mandated ethanol in Minnesota.

    We jokingly thought the reasons for lower fuel economy in Minnesota could be because:

    1. Minnesota drivers chronically drive around with underinflated tires.

    2. All roads in Minnesota go uphill.

    3. Minnesota drivers always drive into a headwind.

    The truth is I can’t point with certainty to the real reason for the big difference in fuel economy between Minnesota and Wisconsin. But the obvious thing that jumps out is that they mandate ethanol while Wisconsin doesn’t.

    It will be interesting to see what happens after Minnesota goes to mandatory E20 which they are about to do.

    Increased fuel tax revenues

    One interesting thing I did discover is that because of their lower mileage figures, Minnesota collects more fuel tax revenues than they would if their drivers were more economical.

    Minnesota’s gas tax is $0.22 per gallon. If their average fuel economy was the same as Wisconsin’s, they would collect about $69 million less each year in fuel tax revenue.

    That has made me jokingly think, “What if the real reason for mandating ethanol in Minnesota was to increase fuel tax revenues?” How Machiavellian would that be?

  12. Hmmm. Your 2005 Vehicle Use table shows 91.578 billion km for MN, which converts to 56.904 billion miles vs. your 56.570 number. The table I used also shows 56.904 if you sum the rural and urban VMT columns. So at least our tables agree 🙂

    Anyway, these differences are too small to matter. But I do think the proper way to do the math is to subtract out the “Percent Truck” portion of VMT since trucks primarily use diesel vs. gasoline. MN passenger vehicle miles would then be something like:

    (27.867 – 9.0%) + (29.037 – 5.4%) =
    52.828 billion miles

    and 52.828/2.735 = 19.3 MPG

    It’s still not a perfect measure as it doesn’t account for diesel cars and gasoline trucks, but those effects should be small and more or less the same across states. (Percent trucks, on the other hand, can be large and vary dramatically across states).

    None of this changes the result that MN drivers average lower MPG than WI drivers. As I said, though, this was true in 1996 as well. Articles about MN’s new E20 mandate often mention the E10 mandate has been in place since 1997.

  13. Re Scott Nance

    That video was lame. The guest was interested in Ag policy and specifically in limiting Ag production. Also, her energy knowledge seemed weak. I would have asked her if there was any biofuel effort that she would support. My guess is no.

  14. I know this is not related to this thread, but someone should check this out:


    It is a link to an article about someone using radio frequencies to “burn water”….. maybe someone would have time to look into the thermodynamics of the process and calculate the energy flows. could be more bad info that leads to wasted research money chasing a negative energy balance.

  15. RE Annonymous,

    anytime someone claims to be “burning water” you should get ready to be skeptical. They are splitting the water, usually by electrolysis, but in this case using radio-waves, and then burning the hydrogen. The amount of energy required to split the water will always be greater than the amount of energy obtained through burning the hydrogen. This guy may have stumbled upon a novel method for splitting water, but not free energy.

    By the way, the cancer treatment he claims to be working on sounds very similar to some work being done at Rice University

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