E85 vs. E10

James Jeude, a reader of my blog, sent me an email raising an interesting point questioning E85 as it “makes no mathematical sense.”

Some valid points are brought up as summarized in this table:



“A typical gasoline engine can run a mixture of 10% ethanol with no modifications. This mixture is commonly found in the Midwest today, and is the result of a chain of production subsidies and tax breaks that bring it to the consumer's pump.  No modification is required on the consumer's car.”


“An E85-compatible car and a distribution system supporting E85 requires severe modifications to the engine and the infrastructure.  An E85-enabled gas station must have a steady supply of E85-enabled cars to be effective.”


Skeptics looking at this table will say that E85 is still at its infant years and will still have a larger affect on the economy in the future. This is not the case, especially in the years to come, as Mr. Jeude creates a hypothetical scenario comparing which fuel, E10 or E85, will be more efficient in the future.

The scenario: If we have enough corn to convert 10% of America’s gasoline supply to ethanol, in what way do we distribute this?

The Options:

E10: If choosing E10, we could have 100% of cars run on 10% ethanol mixture. There is also no need for any new modifications on these cars as pointed out earlier. The portability of cars and E10 across the country is unlimited.  

E85: If choosing E85, we could have 11.7% of cars running on 85% ethanol. 11.7% of all cars would need modifications to be E85 compatible. Its portability would also be very poor as stations would need to have a large amount of E85 cars in the area to produce business. To be most effective, E85 cars would need to stay near E85 fuel sources.
The Verdict:

E10 in scenario

E85 in scenario

-100% of cars run on E10

- Changes required to the inventory of existing automobiles: zero

- Portability of cars and E10 across the country: unlimited


-11.7% of cars run on E85

- Changes required to the inventory of existing automobiles: 11.7% of all cars

-Portability of cars and E85 across the country: poor

It is evident that E10 in this scenario heavily out favors E85. Concluding from this, it currently makes no sense, to use E85, until we have produced more than 10% of US gasoline from ethanol. Only until then E85 will be a viable option, but until now, E10 should be the one that is commercialized since it is more efficient. 

To the investors:
"I would recommend that the investor that intends to make a play in ethanol keep a very close eye.  No, not a close eye on the fundamentals, which make no sense, but a close eye on the direction of investor and public sentiment.  If you think can time the turning point, go for it.  If you're waiting for corn ethanol in general or E85 services in particular to catch on and generate a positive ROI to sustain your investment's stock price, be aware that the fundamentals are working against you."


What did you think of this blog article?

  • No trackbacks exist for this entry.

Display comments as (Linear | Threaded)

  • 5/17/2006 2:33 PM BioConversion Blog wrote:
    If it the cost of manufacturing a flex-fuel model of a car cost appreciably more to the consumer, then you would have the chicken-or-egg conundrum on E85. But I have heard that it costs between $0-$200 for the production line. We already have roughly half a million flex-fuel cars operating in this country.

    I propose that we institute a policy like Brazil has that mandates that all cars sold in the U.S. after 2007 be flex-fuel compatible. Then gas stations would have a reason to consider installing E85 pumps and consumers would see real price depressing competition at the pump.

    Simply announcing the policy might have a sobering effect on foreign oil producers who seem increasingly prone to leverage their current advantage.

    On the other hand, in California we import 95% of the ethanol we use. We have four E85 equipped gas stations. We buy 25% of the ethanol produced in the U.S. to blend as an oxygenate (at 5.67%) in our gasoline. We will have a ready demand for ethanol for years to come without having to install one more pump. So the issue here isn't about need, it's about education and behavior. It's also about local production of ethanol which, I submit, is going to come from bioconversion of waste.
    Reply to this
    1. 5/22/2006 10:45 PM James Jeude wrote:
      Hi, it's the E10 vs E85 author here. My point was very, very, very simple. Until we meet 10.000001% of our country's gas needs through ethanol, we should have EVERY gallon of gas as E10 rather than having a much smaller number of gallons running E85 and the rest running ... well, let's call it E0. That was my point: 100% of cars with 10% ethanol = same as 11.7% of cars with 85% ethanol. We are FAR away from having 10.000001% Ethanol. (I include the decimals to make a point: E10 is here and now and universal and should be our only goal until we think we can achieve more than 10% of our needs through Ethanol.)

      I am waiting for someone to contradict my math. Stil waiting.
      Reply to this
Leave a comment

Submitted comments will be subject to moderation before being displayed.

 Enter the above security code (required)


 Email (will not be published)


Your comment is 0 characters limited to 3000 characters.