Removing Ethanol from Gasoline

[Nerys]

I thought higher octane and compression gave you more POWER not more Efficiency?

From what I understand Diesel's don't get better FE because they use higher compression They get better FE because Diesel simply contains more energy per unit than gasoline.

Here is a list of Flex Fuel Vehicles ie vehicles designed to use E85 and every one of the cars that might lean toward fuel efficiency ie the small 4cyl engines see AT LEAST a 30% gain in FE from E85 to Gasoline

http://www.fueleconomy.gov/feg/byfueltype.htm

some of the lager V6 vehicles see a little less than 30% gains but I think thats mostly because they are larger heavier vehicles and can "use" the extra power (ie they get crappy FE from the get go)

For example in my club wagon towing a trailer or boat has ZERO effect on my FE because I have "surplus" power as it is and its a drag over power situation limiting my FE.

[ShadeTreeMech]

I wonder if by making more power I didn't need to downshift as much causing the slight uptick in economy.

As far as diesel engine economy goes, it is a combination of the higher compression and the higher amount of energy in diesel fuel. Direct gas injection engines can take advantage of the power of higher compression while still running gas. By being able to time the injection of the gasoline during high compression the engine is able to produce more horsepower while using less fuel.

I'd have to find it but there is an article about a 5 cylinder compression ignition engine that is under development in Europe that runs on pure ethanol. IIRC the compression ratio was 21:1, and it is extremely efficient.

While those newer engines may be a good improvement, I think the hydrogen fuel cell is going to be the future of transportation; probably not til I'm a grandfather, but there are a lot of good things going for it. Especially if we can start producing electricity with solar wind and nuclear power instead of burning fossils.

[gone-ot]

...higher compression ratio (CR) does, indeed, produce higher efficiency.

[skysailor]

Nerys: Any chance of you posting a picture or two of your fuel "washing" setup? I happened upon this discussion site while searching for information on removing the ethanol from auto fuel for using in my homebuilt experimental category aircraft. Reason is my aircraft has fiberglass fuel tanks and the engine (2-stroke Rotax) is not rated to use fuel with more than 5% ethanol and recommended to use E0 only. You seem to have had good luck with your setup and I would like to duplicate it. Have you ever tested your final, twice-washed, fuel for ethanol content using the qwik test system? Your research is very much appreciated.

[Nerys]

sure goto 94 Metro - Home Page click on metrolog and you will see the pics. YOU CAN NOT duplicate that setup however. The ethanol aggressively attacks the plastic. it lasted through about 35 gallons of gas before it leaked all over the place.

I am also concerned about what ELSE I am removing from the gasoline and any water I might be leaving in the gas. the point of the test was to see if it was worth buying $100 in gas cans and making the 90 minutes each way drive and $17 in tolls to go get it.

it confirmed it was worth it. I will still do it for my lawn equipment and motorcycles though. I just do not trust the Ethanol with my small engines.

my first tank of REAL E0 was quite a surprise. it was far far less than ideal. I added 5.7 gallons of E0 and then drove home.

I drove the 125 miles home with 100 pouinds of extra gas in tanks on the 250 pound trailer with a 200-250 pound kenmore washing machine on the trailer that was taller than my car :-) the GPS also burned me (it got reset somehow to AVOID toll roads) so I ended up taking 309 all the way home before I realized what the dumb thing was doing :-) so stop and go traffic 3/4 the way.

then I took the washing machine another 75 miles or so to our warehouse space and then pick up two sheets of 4x8 foot OAK flooring on plywood with beams (free on craigslist) home 50 or so miles.

then drove back up to the mountains and refilled on E0 and my Fuel Economy STILL manages to jump from 46 on E10 to 50.14 on 5.7 gallons of E0 mixed with E10

Thats just a WOW to me.

Higher Compression. Yes and no. it can but usually DOES NOT produce higher FUEL efficiency. in fact the opposite it usually produces higher POWER efficiency but LOWER fuel efficiency.

ie more oomph but but also more slurping.

at the RPM's I run I am not even in the car's power band so PE is irrelevant to me. I keep it at 50mph or so around 1600rpm. optimal power efficiency is over 3000rpm.

As for diesel engines no that is not entirely correct. it is not a combination of higher compression and higher energy.

its just higher energy.

Higher compression is a side effect of the lack of a spark plug and the need to "ignite" the fuel by SQUEEZING it to the ignition point.

IE its the "means" in which a diesel engine runs and has little directly to do with efficiency though it does result in more POWER efficiency (but this hurts Fuel efficiency if you USE this power increase in efficiency)

[rmay635703]

Originally Posted by Nerys

As for diesel engines no that is not entirely correct. it is not a combination of higher compression and higher energy.

its just higher energy.

Higher compression is a side effect of the lack of a spark plug and the need to "ignite" the fuel by SQUEEZING it to the ignition point.

IE its the "means" in which a diesel engine runs and has little directly to do with efficiency though it does result in more POWER efficiency (but this hurts Fuel efficiency if you USE this power increase in efficiency)

Not sure where this myth with comes from, even very old diesel engines are more thermodynamically efficient than most gasoline engines accross various load ranges. The reasons are fairly simple

1. More refined, to spec designs,

diesel engines must be built to higher standards to physically function and gain some efficiency from better tolerances and design.

2. No throttle

Diesel engines operate at nearly the same efficiency across their "Normal" power band including idle and low load situations. Gasoline engines simply cannot do this, they use much more fuel than needed at low throttle positions.

That said I am certain you could outperform thermodynamically on many gasoline engines as compared to a diesel IFF you hold that gas engine at one RPM, but most cars are not used this way meaning a diesel wins out over normal driving conditions

Most diesel engines like gassers suffer from low efficiency near & at WOT especially naturally aspirated, so no race car driving for you.

Cheers
Ryan

[Nerys]

Filled it up with precisely 10.15 gallons of gas (10 gallons 2.5 cups)

both fills were to the tippy top fuel vislble at the entry point so its an accurate fill.

Note this was towing an over 500 pound trailer 155 miles home (270 pounds of fuel and the trailer) and stuck 40 minutes in philly traffic another day.

Oh yeah. even with all the towing I am over 5mpg over my previous best record normal driving on E10) Can't wait to see what I get on this tank. percentage of E0 approaches unity on this tank. should be less than a cup of E10 (so 1/10th of 1 cup of ethanol) in the tank or less.

ie Pure E0 no washed gas.

53.2mpg

Lets see what I get this tank

[Allch Chcar]

Nerys,
Diesel only has 10% more energy per gallon than Gasoline. Read the LHV for Gasoline/Diesel.
Higher compression increases the power by increasing the thermodynamic efficiency. Usually it's mixed with a high revving sports cars because high rpm cams bleed off compression which means they don't make very much torque at low RPM. A good example of high compression in an economy car is the First Gen Honda Civic Hybrid, 88ft-lbs of torque at 2800RPM from a 1.3Liter and 10.8:1 Static Compression on regular grade gasoline. Peak efficiency for a spark ignition engine is around 17:1 and cannot be done on Gasoline with a spark plug. Diesel engines run leaner than Gasoline and use compressed ignition but they usually need a turbo to keep generating power past 3k RPM.

It looks like washing Gasoline is working for you. The change in MPG is ridiculously higher, 16% more MPG?

[Nerys]

Its even worse for my other vehicles.

the van went from 19mpg to 13-14mpg

The jeep dropped to 17mpg from 23mpg (I can sometimes still get 19 if I get wawa E8 and REALLY baby it)

Using washed gas it went back to 21+ mpg (and thats still 25% e10 in the tank and heavy amounts of idling and yanking :-)

Back to E10 but I do not have the cash to "refill" the tank just yet so I don't know the MPG of the return to E10 tank. When I do I will have a nice little mini ABA for the jeep.

[ShadeTreeMech]

LOL I just noticed your nickname for the Voyager. V ger :P

a fan of Star Trek, Eh?