Ethanol use in gasoline...facts and fiction?

[ZR1Vette]

Many states use a blend of ethanol and gasoline at their pumps...and here is the PR from the American Coalition for Ethanol:

Every major automaker in the world approves the use of
E-10 Unleaded (10 percent ethanol/90 percent ordinary unleaded gasoline) under warranty. Ethanol adds two to three points of octane to gasoline, helping improve engine performance. Ethanol helps keep fuel injectors clean—and it lowers the levels of toxic exhaust emissions.
Ethanol is an alcohol that is used in gasoline—resulting in a cleaner-burning fuel with higher octane. Ethanol is currently blended into more than 50 percent of the nation’s fuel supply.

Corn is the primary feedstock for ethanol production. About 20 percent of the nation’s corn supply went into ethanol in 2007—some 3.0 billion bushels. Ethanol can also be made from other grains such as sorghum as well as from “biomass” sources such as corn cobs, cornstalks, wheat straw, rice straw, switchgrass, vegetable and forestry waste and other organic matter.

and

For every barrel of ethanol produced, 1.2 barrels of petroleum are displaced.

Of course the spin from ACE would only be positive leaving out a few issues such as (1) early fuel injectors [such as found on the MY 90 & 91 ZR-1s] are ethanol intolerant requiring replacement of injectors with ethanol tolerant versions and (2) higher % ethanol reduces mpg and on a 25 mpg car can be 1-2 mpg reduction...higher on premium performance cars. NOW... for the fiction part... ever seen the stickers on pumps that note "ENRICHED WITH 10% ETHANOL" and you assume you are getting no more than 10% blend. Not so... was discussing effects of ethanol on the early ZR-1s with a causal friend who is a franchise owner of a local Exxon/Mobil station and he gave me a bit of a shocker news... some local Exxon/Mobil stations in the Northern Virginia area tested the ethanol content of the gasoline at the pumps and at his station came out 19% ethanol and at two stations in the Dranesville area 40% .

He said stations have absolutely no control over ethanol content from the distributor so many (like he just did) have upgraded their storage tanks to include a separate ethanol tank so they can blend at the pump. The trend is to have ethanol blends between E10 (10 percent ethanol) and E85 (85 percent ethanol) due to the installation of ethanol “blender pumps.” These special fuel pumps allow consumers to choose which ethanol blend they prefer, including E10, E20, E30, E40 and E85 – or whatever blend of ethanol and gasoline the station owner chooses.
To create these blends, the blender pump automatically combines the appropriate percentages of E85 and unleaded gasoline. For example, an E20 blend uses 24 percent E85 and 76 percent regular unleaded.

Also now to a bit of economics... if gasoline is sold as 10% ethanol meaning 90% petro based and we see a direct correlation cost per barrel sweet crude to cost per gallon gasoline... where do we see the cost of ethanol which is cheaper than gasoline... OK we pay (example only) $3.00 per gallon of mid grade which contains "10%" ethanol and lets say we calculate cost of 1M gallons which is $3M. Now make that 10% ethanol 20% ethanol which means 10% more gasoline is displaced which would be 100,000 gallons and at $3 per gallon that comes to an extra $300K minus cost of ethanol at $.88 per gallon [$88K x (20%)] thus $282K to someone and it ain't the consumer.

Just something to ponder... do the math for 30% and 40% and numbers get better. These are all round numbers and are not exact... just used as an example

[QB93Z]

Michael,

Interesting info. Do you know if the ethanol compliant components still work OK at E85 mixtures? I seem to remember a case where a driver recovered damages for repairs to his car he claimed were required because a gas station mistakenly was pumping E85 instead of E15.

Jim

[Kevin]

post mid 1992 there is no correlation between PPB and PPG

[Aurora40]

Are you sure about that 19-40% test? I would imagine a car designed around 100% gasoline would have a hard time adjusting for 40% ethanol.

If you are concerned about this, you could watch the fuel trims. They would be extremely high with that much ethanol. Also the FSM has a test outlined for determining the volume of alcohols in fuel which should work for ethanol. It basically involves measuring how much water the fuel will absorb.

You are right on, though, about the design requirements. Newer cars must handle E10 because the clean air act allowed for it in reformulated gasoline. However, I believe that was introduced somewhere around 1992. There are obviously cars on the road that are older than this, though.

I'll also make a general statement. If E85 were more prevalent in Virginia, I'd love to run it. I believe the car would/could make about 5-10% more power with no other changes. It would also make the car more suitable for boost. And my money won't go to terrorist-producing countries.

[Locobob]

The change from pure gas to E10 cost me about 3mpg on the freeway. I also lost quite a bit of power on the dyno with E10 in the tank. I think the culprit behind the power loss is that my car was tuned pretty aggresively on straight gas and the added ethanol is causing a lean condition resulting in knock retard. The fuel mix needs to be richer with E10, according to my sources stoich for E10 is about 14-1 vs 14.7-1 for straight gasoline. For power enrichment you would want to see A/F in the 12-1 ballpark vs 12.5-1 for gas. When I get some free time I'd like to do some more testing/tuning on this issue. Pure ethanol has a higher octane rating than gas but you are not getting a freebee at the pump. Generally if the sticker on the pump says 91 octane you are getting 91 octane - ethanol included.

I've read that the Corvette race team used E10 in the 2007 season, anyone tight with the team want to inquire about tuning changes? Bet they have some good info on the subject.

[ZR1Vette]

Do you know if the ethanol compliant components still work OK at E85 mixtures? I seem to remember a case where a driver recovered damages for repairs to his car he claimed were required because a gas station mistakenly was pumping E85 instead of E15.

As I have researched a none flex fuel engine running on E85 can have damage to certain components of the engine and will not run correctly (different tune).

Are you sure about that 19-40% test? I would imagine a car designed around 100% gasoline would have a hard time adjusting for 40% ethanol.
Am I sure???... only as far as the gas station owner was pretty detailed about the tests and equally disturbed that they (station owners) could not get a guarenteed % of ethanol from the distributor. And I agree at 40% the engines (non flex fuel) would run fairly poor...

Locobob...hope you do the testing...be very interested in the results! Wonder if there is a low cost % ethanol tester on the market?

[Aurora40]

Originally Posted by Locobob

I've read that the Corvette race team used E10 in the 2007 season, anyone tight with the team want to inquire about tuning changes? Bet they have some good info on the subject.

They are using E85 for the 2008 season. I don't recall hearing about an E10 change last year, but it might not have been very big news?

Originally Posted by Aurora40

They are using E85 for the 2008 season. I don't recall hearing about an E10 change last year, but it might not have been very big news?

ALMS has been on the leading edge of technology for many years. Much more so than Nascrap.

In 07 they ran on E10, and the challenge was to run E85 for 08. As a result of the decreased mileage the Corvette team and any other team is given a larger fuel cell.

[Aurora40]

If I recall, NASCAR only recently stopped using leaded gasoline. I always found it amusing that their "Car of Tomorrow" would have a carburetor, leaded gas, a 4-speed manual, and 15" steel wheels.

It's sad, there is not technological advances in nascar, and that is where all the money is going.