Ethanol - power loss and less fuel economy in common engines

[Nemesis]

Here is some info I found on Wikipedia that shows that 10% ethanol mixtures(common today) can seperate at temps higher then 70 degrees causing "water slugs" in your fuel system. In specially made engines Ethanol is more fuel efficient due to higher conmpression, but actually decreases power 34% in regular engines and gives WORSE fuel mileage in normal engines. The only reason we are getting 10% ethanol is because it cuts the cost of the gas by pennies!





Fuel economy
In theory, all fuel-driven vehicles have a fuel economy (measured as miles per US gallon, or liters per 100 km) that is directly proportional to the fuel's energy content.[27]In reality, there are many other variables that come in to play that affect the performance of a particular fuel in a particular engine. Ethanol contains approx. 34% less energy per unit volume than gasoline, and therefore in theory, burning pure ethanol in a vehicle will result in a 34% reduction in miles per US gallon, given the same fuel economy, compared to burning pure gasoline. This assumes that the octane ratings of the fuels, and thus the engine's ability to extract energy from the fuels, are the same.[14][15] For E10 (10% ethanol and 90% gasoline), the effect is small (~3%) when compared to conventional gasoline,[28] and even smaller (1-2%) when compared to oxygenated and reformulated blends.[29] However, for E85 (85% ethanol), the effect becomes significant. E85 will produce lower mileage than gasoline, and will require more frequent refueling. Actual performance may vary depending on the vehicle. The EPA-rated mileage of current USA flex-fuel vehicles[30] should be considered when making price comparisons, but it must be noted that E85 is a high performance fuel, with an octane rating of about 104, and should be compared to premium. In one estimate[31] the US retail price for E85 ethanol is 2.62 US dollar per gallon or 3.71 dollar corrected for energy equivalency compared to a gallon of gasoline priced at 3.03 dollar. Brazilian cane ethanol (100%)is priced at 3.88 dollar against 4.91 dollar for E25 (figures July 2007).


[edit] Ethanol fuel mixtures
For more details on this topic, see Common ethanol fuel mixtures.

Hydrated ethanol × gasoline type C price table for use in BrazilTo avoid engine stall due to "slugs" of water in the fuel lines interrupting fuel flow, the fuel must exist as a single phase. The fraction of water that an ethanol-gasoline fuel can contain without phase separation increases with the percentage of ethanol.[25]. This shows, for example, that E30 can have up to about 2% water. If there is more than about 71% ethanol, the remainder can be any proportion of water or gasoline and phase separation will not occur. However, the fuel mileage declines with increased water content. The increased solubility of water with higher ethanol content permits E30 and hydrated ethanol to be put in the same tank since any combination of them always results in a single phase. Somewhat less water is tolerated at lower temperatures. For E10 it is about 0.5% v/v at 70 F and decreases to about 0.23% v/v at -30 F.[26]

In many countries cars are mandated to run on mixtures of ethanol. Brazil requires cars be suitable for a 25% ethanol blend, and has required various mixtures between 22% and 25% ethanol, since of July 2007 25% is required. The United States allows up to 10% blends, and some states require this (or a smaller amount) in all gasoline sold. Other countries have adopted their own requirements. Beginning with the model year 1999, an increasing number of vehicles in the world are manufactured with engines which can run on any fuel from 0% ethanol up to 100% ethanol without modification. Many cars and light trucks (a class containing minivans, SUVs and pickup trucks) are designed to be flexible-fuel vehicles (also called dual-fuel vehicles). In older model years, their engine systems contained alcohol sensors in the fuel and/or oxygen sensors in the exhaust that provide input to the engine control computer to adjust the fuel injection to achieve stochiometric (no residual fuel or free oxygen in the exhaust) air-to-fuel ratio for any fuel mix. In newer models, the alcohol sensors have been removed, with the computer using only oxygen and airflow sensor feedback to estimate alcohol content. The engine control computer can also adjust (advance) the ignition timing to achieve a higher output without pre-ignition when it predicts that higher alcohol percentages are present in the fuel being burned. This method is backed up by advanced knock sensors - used in most high performance gasoline engines regardless of whether they're designed to use ethanol or not - that detect pre-ignition and detonation.

[Nemesis]

OH, I forgot: It also reduces our dependance on foreign fuel supply by a fraction too.

[fr0stb1t3]

Originally Posted by Nemesis

OH, I forgot: It also reduces our dependance on foreign fuel supply by a fraction too.

And raises food prices all over the world. YAY

[SILVER ANNIV]

We always got 23 mpg city and 28-30 mpg highway in our Vues - until 10% ethanol was mandated. Now we're lucky to get 20 and 24. And with the winter blend it's usually around 18 city. Our poor Sky has always been stuck with using this crap, so I'd love to see how much better she could do on pure gas. I'm between 26 and 28 mpg with mostly combined driving.

[compdoc777]

E85 with the proper tune should give you about 20% more power. Who cares about the mileage. E85 is a $1.00 cheaper!

[rufusmacblorf]

I've seen several local gas stations touting "no ethanol!" on their signs. The prices are about $0.25 per gallon more, but there seen to be plenty of customers willing to pay the difference.

[Nemesis]

Originally Posted by compdoc777

E85 with the proper tune should give you about 20% more power. Who cares about the mileage. E85 is a $1.00 cheaper!

The Wikipedia entry says that it takes a higher compression ratio to get better performance from 100% ethanol (E85=85% ethanol). They say that the compression ration needed to achieve this would render the engine useless for regular gas. On our standard engines it actually reduces the effectiveness of the fuel because ethanol does not create as much specific energy as gasoline. If you have an engine that is created to handle E85, then you have the ability to change the compression ratio(or your engine has the ability to do so) to compensate. Most cars out there are NOT created to handle this fuel and therefore suffer 34% power loss and fuel mileage goes down, both because the fuel creates less power and because most people are probably pushing the gas more to get the same power.
Case in point: I have been asking around to avoid E10, but got trapped the other day because I was on E. I immediately found that power was dropped dramatically throughout the rev range. I filled up to half tank and burned it all up in 1 day. This same amoutn of gas would have lasted me 2-3days on pure gasoline. I Have not looked at my gas mileage meter yet, but it previously read between 28-33mpg. I'll try to look today and see what it says. I can only find one place around here that doesn't use E10, but I am willing to pay the price to avoid the power loss. Also, E10 damages lawn mowers. The local news here in Birmingham did a report and showed lawn mowers going bad because ethanol leaves a residue behind because the engines are not able to completely burn ethanol away. Over time the ethanol enamel causes engine failure. Supposedly this is for smaller engines only, but I wonder if this will eventually include 4-cylinder cars that are not designed to handle E10?

[TulsaSky]

First, I finally tried the E85 in my 06 Flex Fuel Impala I went from a average 28 miles per gallon to 21, granted over a year ago I got a service bulletin stating that if I used E85 on a regular basis to get a ECB re-tune, which I never did since at the time no one sold E85 in the area. My options are to drive 5 miles out of my way to fill up on E85 pay for shop time to re-tune the car hoping to get better MPG or just use regular unleaded, back to Wally Worlds cheap gas.
Second, or local Sinclair station is advertising "NO Ethanol", OK so are state mandates they cut it by 10% with something so what are they using? I know in both the Corvette and Sky the owners manual clearly states to NEVER use menthol so what is Sinclair using?

TulsaSky

[compdoc777]

Don't trust the information. E85 you only need to tune for the fuel. Does not take high compression. What do you think the turbo does? The turbo compresses the intake charge so turbo applications get more power.

Example: On my Supercharged RSX Type S we ran 301 whp with regular fuel. Then tuned with E85 and ran 320 whp. Now the compression on the RSX is 11:1 so that would be higher compression, but most cars today run a higher compression ratio.

Notably one will either need a canned E85 tune or a programmable ECU like I have on the RSX to do this, but any OBDII car can be tuned to run E85.

The gas mileage does go down, but then again you are not paying more for gas are you.

[Nemesis]

Originally Posted by compdoc777

Don't trust the information. E85 you only need to tune for the fuel. Does not take high compression. What do you think the turbo does? The turbo compresses the intake charge so turbo applications get more power.

Example: On my Supercharged RSX Type S we ran 301 whp with regular fuel. Then tuned with E85 and ran 320 whp. Now the compression on the RSX is 11:1 so that would be higher compression, but most cars today run a higher compression ratio.

Notably one will either need a canned E85 tune or a programmable ECU like I have on the RSX to do this, but any OBDII car can be tuned to run E85.

The gas mileage does go down, but then again you are not paying more for gas are you.

Despite this, the ethanol gives off a lower amount of energy at the current/same compression. The turbo is designed to create the power we bought it for, with gasoline. It does not currently create this same power with ethanol.

"The gas mileage does go down, but then again you are not paying more for gas are you?" - I pay maybe .25 more per gallon for pure. This comes to roughly $2.50 more per fill up(fill up costs $55.00). So If I use the ethanol (E10) I will fill up for $52.50, pure $55.00. If you are losing 5mpg with E10 and traveling an hour like I do, then the result I had was my fuel mileage was almost cut in half. This means that with pure I spent $55.00 over a 2.5 day period, with E10 I spent $105.00. See my point? These are my real world numbers using the same daily route at the same speed over a 50minute period.

Bottomline: whether a tune would help or not, our production skys are not designed to run on ethanol, resulting in lower MPG and 34% drop in power at current compression settings.

[compdoc777]

Originally Posted by Nemesis

Despite this, the ethanol gives off a lower amount of energy at the current/same compression. The turbo is designed to create the power we bought it for, with gasoline. It does not currently create this same power with ethanol.

"The gas mileage does go down, but then again you are not paying more for gas are you?" - I pay maybe .25 more per gallon for pure. This comes to roughly $2.50 more per fill up(fill up costs $55.00). So If I use the ethanol (E10) I will fill up for $52.50, pure $55.00. If you are losing 5mpg with E10 and traveling an hour like I do, then the result I had was my fuel mileage was almost cut in half. This means that with pure I spent $55.00 over a 2.5 day period, with E10 I spent $105.00. See my point? These are my real world numbers using the same daily route at the same speed over a 50minute period.

Bottomline: whether a tune would help or not, our production skys are not designed to run on ethanol, resulting in lower MPG and 34% drop in power at current compression settings.

Yes, I am not talking taking a stock tune Sky and run E85 you have to be tuned. All different fuel, cam, parimeters.

I feel like I am stepping back in time with this car. Since I have Hondata Kpro and everything that needs to be changed is easily adjust within seconds real time or data logging.

I wonder if AEM will come out with an EMS for the sky.

[rufusmacblorf]

Have any of the tuner vendors (Eloy, Hahn, etc.) done dyno tests on ethanol versus non-ethanol fuel? I'd be very interested in hearing some measured results.

[compdoc777]

Originally Posted by rufusmacblorf

Have any of the tuner vendors (Eloy, Hahn, etc.) done dyno tests on ethanol versus non-ethanol fuel? I'd be very interested in hearing some measured results.

BSR is supposed to be working on a E85 tune for our cars.

[Nemesis]

Originally Posted by TulsaSky

First, I finally tried the E85 in my 06 Flex Fuel Impala I went from a average 28 miles per gallon to 21, granted over a year ago I got a service bulletin stating that if I used E85 on a regular basis to get a ECB re-tune, which I never did since at the time no one sold E85 in the area. My options are to drive 5 miles out of my way to fill up on E85 pay for shop time to re-tune the car hoping to get better MPG or just use regular unleaded, back to Wally Worlds cheap gas.
Second, or local Sinclair station is advertising "NO Ethanol", OK so are state mandates they cut it by 10% with something so what are they using? I know in both the Corvette and Sky the owners manual clearly states to NEVER use menthol so what is Sinclair using?

TulsaSky

That actually brings up a good point: I know gasoline is regularly tested for quality. Does anyone know if ethanol amount tested or required by law to be posted for the customer to see? I have seen that most gas stations that use E10 have little stickers stating "this gasoline contains 10% ethanol". However, are they required to disclose this information by law? Is it state law or federal? I know my source of pure is telling the truth because I can definitely feel the difference. For the longest time I couldn't figure it out and I kept taking the RL back to Saturn to figure it out and they couldn't. Once I figured it out there is definite difference.
LATEST NEWS: - I went and filled up 3/4 tank on the pure and all the power is back again. Big difference.

[rufusmacblorf]

So ethanol in my gasoline = water in my scotch? This really is a problem!

[SILVER ANNIV]

We just got back from a long weekend in Kentucky. We did a lot of driving around. Got to fill up at a Chevron with pure gas a couple of times. We paid exactly the same amount there that we spend for the 10% ethanol in PA. $4.19 for 93 octane. We went up to 32 mpg and the car just flew through twisties and up and down the mountains. I wish I could stay with the pure gas at home.

[2sky4]

Wasn't ethanol originally used as a solvent? Imagine what it is doing to seals and other components in your engine. Studies have shown that the ethanol has caused deteriorization of rubber and any silicone products. Any thoughts on the long term effects of ethanol? Especially on a non-flex engine.

[Nemesis]

Originally Posted by 2sky4

Wasn't ethanol originally used as a solvent? Imagine what it is doing to seals and other components in your engine. Studies have shown that the ethanol has caused deteriorization of rubber and any silicone products. Any thoughts on the long term effects of ethanol? Especially on a non-flex engine.

Birmingham News did a story on how the ethanol destroyed lawnmower engines because it left an enamel. They explained this happend because the engines did not fully combust the ethanol.

[MidniteBlues]

My biggest fear in Florida now is that our illustrious traveling always missing governor signed a bill making it "mandatory" to include "up to 10%" ethanol in all fuels. This is suppose to help cut gas cost, you know what it ain't happening... I hate when the goberment makes these decisions without the PEOPLE voting for it.. AND he is a GD republican, and now he also agrees to open up the gulf to drilling, which i always wanted any ways, better us than the dam Cubans/Chinese doing it. BUT his r