Sunday, June 12, 2022

15% Ethanol

I received several messages from a friend last night. He is bothered by the sudden approval of 15% ethanol in motor fuels. He listed many reasons why it bothered him: People will be starving this winter and next, governments will be overthrown, first-world countries will be overwhelmed by angry, hungry migrants.

But those consequences are beyond his control. He observed that I used to work in the automotive industry. "Do you have any deep-knowledge about what 15% ethanol will do to my motor vehicles?"

Sadly, I did not. However, I have friends.

Establishing plausible deniability

When we retired from the company we signed a document that acknowledge that we could be fired retroactively if we divulged closely-held or embarrassing information (i.e. trade secrets).

Since the text that follows, if true, tickles the edge of that definition I am going to tell you that what follows is fiction.

The Margin of Cheat

15% ethanol: You have probably already run several tanks of it if you live in Wisconsin or Minnesota even thought the legal maximum is 10%.

Ethanol is cheaper than gasoline. Sliding a little extra ethanol into the mix "Oops, sorry, the shutoff didn't work" is a great way to make a little extra money for the blender and still sell your gasoline cheaper than the guy down the road.

The mixing often happens at a distributor...the guy with the five million barrel storage tanks.

Why Wisconsin and Minnesota? 

In the 2005 time-frame there were multiple vehicle failures that were consistent with excessive ethanol in the fuel. Primarily metal parts corroding before testing suggested it would happen.

After exhausting most other possible causes, engineers went around and collected gasoline (nominally 10% ethanol) at gas stations where the failures were clustered. The median ethanol content was 12%.

My friend assumed the excessive ethanol was due to state inspectors winking and looking the other way. Perhaps they were "renewable energy" zealots. Maybe they came from a family of corn farmers or had a financial interest in an ethanol plant. Maybe they got a few bucks to look the other way. Maybe all three reasons.

The company protected itself by "hardening" the system to withstand a steady diet of 15% ethanol. Because of the way the cadence of upgrades is staggered across different models, the hardening occurred between roughly 2008 and 2012. Bottom line, if you are driving a vehicle that is 10 years old or newer, you are probably OK for 15% ethanol.

The kicker is that the margin-of-cheat will stay the same. 15% mandated maximum will mean 18% typical at the pump. For the record, 22% ethanol is the most corrosive percentage. 85% ethanol is less corrosive than 22% but the 85% does present challenges to plastics and rubbers that the 22% will not.

Side notes

Use of 15% ethanol will likely invalidate the warranty on your outboard motor, you lawn mower and your chainsaw.

In most cases, the damage due to excessive ethanol is progressive and accumulative. But if the blenders get too crazy with ethanol, it can result in required spark-advance drifting outside the limits programmed into the PMC and unburned fuel and oxygen can make it to the catalytic converter and fry it.


  1. It seems appropriate that "pesky customers" get an ethanol tester and prepare for the American response--- many legal challenges.

  2. E15 is BAD NEWS. Causes mucho issues in older engines.

  3. My 2011 Jeep owners manual specifically states that manufacturers warranty is void if fuel is >10% Ethanol.

  4. Old retired mechanic here with thousands of engine , carb , rebuilds under my belt . I have watched these many years as the ethanol was introduced and one cannot help but notice the damage done to every component in the fuel system by ethanol . It was one of the biggest scams and mistakes of my lifetime even though it put many thousands of dollars in my pocket over the years . I can find all the honest work I need and more without the gov destroying carbs , injectors , and fuel systems with the ethanol mandate .

  5. Lateral to starving people: the local seed potato growers did not get +/- 5% of normal planted because of wet spots. Even if they got them planted later, they couldn't expect to get them out in the fall. So they don't bother wasting money to try. 95% crop base.
    BUT- 50 percent of what is planted looks terrible. It could just be variety planted, I don't know.
    I guess the upside is you could just plant regular not "seed" potato if you have to.

  6. As of 1 May 22 NASS if USDA said 1% of potato crop planted compared with 39% at the same time last year

  7. Nothing in politics happens by accident. If it happens it was planned. FDR said that before any of us was born. The push to 15% (and higher) ethanol has a number of motivators. Destroying older vehicles is one of those motivators. They want people to give up their old reliables and buy the new hotness...the EV's. The EV's that will have a remote OFF SWITCH the Fed Gov can control. The EV's that can't be charged due to the constant brownouts. In short the Fed Gov is working feverishly to destroy the ability of the average American to travel in ANY WAY other than public transport...that THEY control. When you boil everything that's happening down to one fundamental word it's simple. It's about CONTROL. The only thing that truly matters to the pathological personalities drawn to politics.

  8. Ethanol is very valuable to the blenders - they make money via the cheap additive, as well as via selling of tax credits.

  9. Removing the alcohol isn't complicated. But the extra work wasn't something I wanted to do. I ran the numbers Saturday, and removing the "15%" of alcohol would mean I'd pay about 5.51 / gallon for gas, plus the work of removing it. Down at Wally world, their no ethanol gas is 5.21. I bit the bullet and went there. Reminds me of 75 cent regular gas and my old Starfire had to have Ethel. $1.12 a gallon...


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