[Article] Better Fuel Economy with Ethanol?

[pgfpro]

Originally Posted by Allch Chcar

87 octane is still 87 octane . It sounds like you're running junk through your engine. Just to be clear they don't sell E10 they sell G90/E10 and some places sell E85. If you're getting ping on cold days it's probably running Lean and as you probably know you need to run richer during colder days. Your ECU is running out of spec. Have you checked your fuel filter? I'll bet you're still running a mix of 87 and 89 octane in your fuel tank, unless you drained the whole thing.

And Ethanol is much higher octane. Get your facts straight. The fuel requirements are different, ethanol requires more fuel to maintain stoichometric.

Mkrusz, mechanics ain't what it used to be. Ethanol and Gasoline doesn't evaporate out of the tank like that in newer cars. Although I can only imagine how long you left the vehicle sitting to let the fuel evaporate.

If you think Corn ethanol is bad, imagine trying to drill for more oil and building more refineries. I used to live in a town that had a plastic plant and an oil refinery, Cancer levels were much higher than normal! Then they built an Ethanol plant.

pgfpro, how close did you get to gasoline mileage? The only way to get better mileage is to up the SCR drastically. If Scania is using 29:1 in their CI bus engines you should know 9:1 in a SI doesn't cut it.

Old Tele man, unless you increased the fuel flow I'll bet it lost power running lean. But how do you figure it lost power?

The big benefit to ethanol in a turbocharged car is the cooling effect it has on the intake, I understand the effect is bigger when dealing with Multi Port Fuel Injection or even Direct Injection. Gasoline has a cooling charge but not nearly as much as Ethanol or even Methanol.

I haven't seen any "real" food shortages. The rice shortage was due to a rapidly jumping price on the market for speculative rice so the farmers held their crop till it calmed down. The corn shortage was due to poor harvest in Mexico and a drought through the country. Food Corn is just a small portion of grown corn and I didn't even know they grew corn in Cali . BTW, the actual water usage for corn is very small. Some dork inflated the number with Zeros awhile back and it was a phony. Corn Ethanol takes less water than Oil. There's a lot of Propaganda going around. Oil is still the biggest Bizness in town. You have to apply salt to just about everything these days. Most of the Pro-Ethanol stuff I've seen has been truthful but the price and distribution are still it's biggest problems.

Yes, an Ethanol Engine can get the same mileage as a Gasoline engine. But they are designed very differently. Ethanol loves compression and works very well with a turbocharger. If Ethanol engines became popular they would have to be built stronger to handle the higher pressure that is more suited to alcohol fuels. Ethanol can run leaner and richer than Gasoline. A Prius with it's 13:1 SCR gets a big power boost just from running Ethanol. Imagine an Insight with a much higher Compression ratio and the ability to run lean!

I did the testing in my 93 Eagle Talon. It would get around 30mpg freeway running gasoline and 25mpg freeway with E85. My CR was 9:1
I have no problem with amount of Ethanol that's being used now. I just don't think its a good idea to increase that amount.

I do understand that my 9:1 CR engine isn't the best choice for ethanol. I believe that a "purposely built ethanol engine" could managed to get great fuel mileage. But the availability is whats in question.

[Allch Chcar]

Old Tele man, wat? You need more fuel flow for E85, NA or SC. If you ran it one tank that's not much of a test. It takes several fillups before the ethanol gets to a higher % and then it takes time for the ECU to adjust parameters for each %. Running NA with low compression is not "Ideal" for alcohol but it will still run better on alcohol than gasoline if its running a good Air/Fuel Mixture. The cooling effect is there turbo/supercharger or not. And every successful E85 conversion should net more power and especially more torque. If not something went wrong.

As for your butt dyno test, are you positive it didn't shift into OD before you hit the hill? 40-45 is a common spot for an auto to slip into OD and if it wasn't shifting up on gasoline that may explain the difference. Just trying to eliminate some variables .

pgfpro, yeah, 9:1 is too low. 25mpg E85 is still better than Gasoline energy wise. Ethanol runs better than Gasoline at any compression ratio, getting the same mileage takes a much higher static compression. But I imagine you enjoy the boost more :P. Does it save you money to run pump gas for daily? Here E85 is priced against Premium but it's only 20 cents cheaper than regular.

My goal is to build a really small engine like a 1.0l Suzuki G10 or Insight 1.0l into a Focus. Rebuilt bottom end with 12.5:1 Compression pistons, and turbocharged with 10-15lbs of boost. Most of Ford's I-4 are Mazda sourced and Ironclad. A G10 complete engine weighs 130lbs compared to the 2.3L in my Ranger at 340lbs! I'd sooner swap in a LS than use a Ford motor . Better Gas mileage in an LS than some of Ford's older Iron Blocks I-4s . Besides being broke and too poor to actually do anything yet, I'm stuck thinking if I get a G13B DOHC I could get over 160HP(SOHC, 200HP DOHC) instead of 120HP with a G10. I've been researching alternative fuels since before I knew the difference between a Focus and a Taurus. I figure with Compression, Turbo, an otherwise dinky motor I can make a RWD Focus really fly. If I use a T-56 from a Corvette it could be fun and fuel efficient. The Irony is Ford is using twin Garrett15's which are exactly the turbo for a small boost G10 .

I'm not an authority on Ethanol but I've spent considerable time looking at the options. It's not that a Mr.Fusion isn't better it's just not an option. It's not that hydrogen isn't cleaner it's that fuel storage is expensive or leaky, it's not very efficient too. CNG requires a NG line and Propane is not a renewable fuel source. Electric is expensive for the range you get and motors are equally expensive for anything with more than 30hp, and heavy.

Ethanol is efficient, it can be affordable, it is more toxic than pure gasoline when mixed with gasoline, it allows for smaller engines for a given HP, and it's renewable. The way I see it, things couldn't be worse for Ethanol. Projects are in the works for better sources of Ethanol. The biggest threat to better Ethanol is lack of interest. Alcohol is a "better" fuel than Gasoline. In exchange for some MPG(But not less efficient) you get a better economy, cleaner fuel(in absence of Gasoline), more power, lighter engines, and eventually a cheaper renewable fuel. I'm weird in that I'd pay more for a renewable cleaner fuel but getting acceptable performance is still a consideration.

[shovel]

I think I'm getting the picture here from a couple folks..

"I RAN A DIFFERENT FUEL IN MY COMPLETELY UNMODIFIED CAR AND IT DIDN'T RUN GOOD SO OBVIOUSLY IT'S THE FUEL THAT SUCKS" ....

[pgfpro]

Please understand that I'm all for ethanol. I love the stuff

For me I just wish I had it in my town and it was more available on the west coast. If it was it would be my fuel of choice for mileage and performance.
As of right now i only have one station that has it and its 40miles from where I live. Its cost is also 22 cents more then regular pump.

[solarguy]

Well, am much as I dislike going down the rat-hole of a discussion about corn based ethanol's "renewable" status...

Most corn grown in the US contributes to significant topsoil loss, which is definitely not good for renewables. Ethanol from corn has, at best, a 1.3:1 EROEI, which is not that great. Many plausible critics of corn based ethanol put the EROEI at 1:1, which would be positively horrific. I think it is somewhere between those two numbers, and still not great. Neither one of those numbers accounts for topsoil erosion.

Finest regards,

troy

[Allch Chcar]

Topsoil erosion? Right. Lets keep running 100% gasoline because farming contributes to erosion.

The better fuel economy with half Ethanol/Gasoline blends has been noted a couple times by individuals. I don't know the exact reasoning. I can only suggest that the compression is favorable at lower blends. Gasoline has a lower ideal compression ratio so it only makes sense that less compression is better with gasoline.

On the topic of fuel efficiency. I'm having no progress finding authentic improvements or information on higher compression for anything but performance or turbo projects. When you compare E83 to G90 you'll gain approximately 5% from just switching over to Ethanol intensive blends due to the knock resistance and cooling effect etc. But that is only on a modern OBDII compliant vehicle, First Gen or Second Generation. Eg. The OBDII mandate began in 96 with Ford they had EEC-III modified slightly to become EEC-IV. The gains were marginal even though OBDII are technically superior in design. In 2001 or so Ford starting implementing GenII or EEC-V which was noticeably better. The biggest gain for ethanol is still on an extremely high compression, beyond Gasoline NA compression ratios or Turbos. With Ethanol that could mean 14:1 on an economy cam. Racers run 16:1 on Methanol/alky but on longer duration cams that bleed off more compression, on Ethanol you're looking at 15:1. The difference is a racing cam with 40* degrees of overlap will lose 8% of it's Dynamic Compression ratio. If Ethanol's max ideal compression was something like 13.7 or so a 15:1 race engine would be just fine at 40* of overlap. A factory cam with about 20 degrees(Geo Metro came with 18) of overlap would be safer at 14:1 because it will lose 4% of it's dynamic compression approximately. With a turbo if you double the air pressure in the manifold for 15lbs of boost your 10:1 Static compression ratio becomes 20:1 before you factor in volumetric efficiency. 90% is a good starting point for Max RPM. With that you get a dynamic compression from a 14:1 Static CR with 90% VE and 96% effective compression, 12.096:1 at full throttle opening.

Now you're going to have to help me out with this one. Unless there is a major jump in energy efficiency from 9.5:1 to 14:1 Static CR that increases fuel efficiency 45% higher you're not going to see equal fuel economy. The only people I've seen running E85 have been getting almost EPA figures. Which we know is not as high as a certain vehicle and engine can get on the road. Also an engine that gets 45% higher energy efficiency is generating 45% more Power from a given amount of fuel. So we know that even if this was true the load decreases with power and fuel efficiency goes down. The only solution I found was of cutting the engine displacement to raise the load and increase the effective fuel efficiency. But to really get good fuel economy you need tall gearing and high load at cruise. Most engines are low load at cruise to allow for more available power during acceleration. The only way to increase available power is to increase compression which is not as effective with gasoline beyond 10:1, upshift or shorten gearing while upshifting is temporary it does cut down economy and gearing can be worked around with wider or more gearing, or go turbo which besides even worse fuel efficiency per unit of power a turbo is generally worse for gasoline than any other option due to the Static CR drops too far below the Ideal Compression for even gasoline.

[rmay635703]

Antidotal but I ran between 33 and 75% e85 in my Buick lesabre for about 2yrs, oddly FE was not significantly decernable from E10 fuel, now if I were to compare to standard gas its also a bit bleak since I have only run 3 partial tanks of real gas over the last 2 years as there doesn't seem to be any of that stuff up here in corn country. I could say about 2mpgs better on real gas but it would be hard to tell since the driving conditions vary so much.

I have been having issues with my FE being about 4-6mpg lower in these winter months, I am beginning to think it must be bad winter gas, anyone know if the gas mix for summer/winter is posted by percentages anywhere?

It seems there are over 140 ingredients in todays fuel but the major components are still important to FE.

[solarguy]

I can assure you, you will care about topsoil erosion when your food costs go up 50% across the board in your lifetime and food shortages get dramatically worse. Never mind the depletion of fossil aquifers to irrigate corn. Water tables in all the major grain producing countries are dropping rapidly due to over use of irrigation. Why waste it on ethanol?

And if the true EROIE is 1:1, then for every BTU of ethanol we produce, we use up 1 BTU of fossil fuel in the farming/harvesting/production of the corn based ethanol. Hard to see how you're getting ahead. At best, it's 1.3:1, so a net gain of 30% on the BTU's.

By comparison, biodiesel has an EROIE of 3:1, give or take a smidge. So, for every unit of fossil fuel you put in, you get 3 units out, a net gain of 2 units. Much better than 0.3 units out.

Finest regards,

troy

[Duffman]

Originally Posted by solarguy

I can assure you, you will care about topsoil erosion when your food costs go up 50% across the board in your lifetime and food shortages get dramatically worse.

It is an error to equate hungry people with food shortages. There is no food shortage at this time.

[roflwaffle]

Duffman FTW! Massive problems w/ food distribution are what we got.