[Article] Better Fuel Economy with Ethanol?

[Mkrusz]

I tried a tank of it back in the 80's. The junk evaperated before I could use it. Hello spark plugs and good bye valves. This reminds me of the old propane injector system. Just another government con in my opinion. I did work as a master ASE mechanic for over fifteen years though.

[shovel]

Interesting that the two derogatory posts (desertbob and mkrusz) are from their respective posters' very first & only post.

I have also used E85 quite a lot in my 2001 S10 v6 and my 1992 Ford Tempo and in two 1991 Isuzu Troopers.

All 4 cars behave(d) exactly the same on E85. Fewer miles per gallon of fuel, drastically more horsepower, and a smoother idle. And on the s10 my check engine light would come on (bank 1 lean code) because of the different stoichometry of the fuel - it no longer does this because I have had the PCM reprogrammed to allow faster sampling and a wider PWM band for the injectors, and have increased line pressure (with a tiny washer behind the FPR spring). On gasoline fuel trim stays about -6 to -9 and on E85 trim stays around +9 to +18.

You can call me fully sold on ethanol. If I could buy E85 more than 2 places in town it's the only fuel I would run. Yes I get fewer miles per gallon, but the net cost per mile is about the same and with a smoother idle and more pep I enjoy the drive more. Not to mention it does support domestic farmers, domestic waste processors (in Phoenix we have a plant that diverts trash from the dump and turns some of it into ethanol) and produces fewer pollutants if my emissions test in the S10 is any indicator.

[Mkrusz]

That's all great if your into spending money. Did you forget the burnt valve problem or was I just blowing smoke?

[gone-ot]

...not everybody's experience with ethanol has been as "good" as yours. Cars, like opinions, vary, so obviously YOMV.

...if I owned a car with turbocharged engine, I'd certainly use E85 just to take advantage of its higher octane rating...assuming the ECU was capable of "using" that higher octane by bumping up the ignition timing and so yield more HP.

...but, my '09 Vibe doesn't have a turbocharger and looses HP instead of gaining it on E85, so I choose to stick E<10 (AZ's manditory "blend") for my reasons. To each, his/her own.

[pgfpro]

I run E85 for my race fuel and regular gasoline for economy fuel.

I did a lot of testing with E85 and tried to see if I could match my gasoline mileage and had no luck. Even with a very aggressive timing map.

[Frank Lee]

Originally Posted by Mkrusz

I tried a tank of it back in the 80's. The junk evaperated before I could use it. Hello spark plugs and good bye valves. This reminds me of the old propane injector system. Just another government con in my opinion. I did work as a master ASE mechanic for over fifteen years though.

If you say so

[shovel]

Originally Posted by Mkrusz

That's all great if your into spending money. Did you forget the burnt valve problem or was I just blowing smoke?

Combustion temperature only gets excessive if you run lean. Under good stoichiometry, alcohol produces lower combustion temperatures and does not burn valves. This should be elementary to an ASE master mechanic.

Since ethanol brings quite a lot of its own oxygen to the party, it requires about a 10:1 air/fuel ratio compared to around 14:1 on gasoline. This would necessitate as much as a +40 fuel trim on a typical, unmodified fuel injection system and as any ASE master tech should know, +25 is about as far forward as a typical ECM will drive its injectors to compensate for altitude changes and typical wear-n-tear - not to mention the injectors themselves may not have additional duty cycle available in low(ish) pressure systems. On gen1 v6 Troopers it's easy, you just disassemble the TBI pod and drill out the fuel pressure regulator ball valve retainer, tap the housing for a screw, and screw down until you get the desired higher pressure. The ECM can trim + or - 25% roughly so assuming your o2 sensor is operating correctly you just fill up your empty tank with e85 and drive around, adjusting the fuel pressure up until the CEL no longer comes on. This turned out to be around +6psi and yes, it will probably reduce the life of the fuel pump but never did in the 70k+ miles I owned either of my Troopers.

My tempo has a piggyback ECU for its dual fuel CNG conversion and although I haven't had cause or desire to reverse engineer it - the car seems to work brilliantly on E85 and when I point a laser thermometer at the exhaust manifold, temperatures are the same on E85 as gasoline. The cat runs about 50-100F cooler though, or appears to, on E85 (i had to measure on different days so atmospheric conditions may skew results)

My 01 Blazer uses a gm vortec 4.3 engine and thanks to a sticky poppet I replaced the fuel injector assembly with GM's fix for the poppet problem, the factory injector assembly that came on 2004+ implementations of the 4.3 vortec. This replacement has an adjustable fuel pressure regulator in it as well, but getting to it requires an awful lot of disassembly so I didn't want to adjust it "by ear" - I got in touch with pcm4less and had them reprogram an ECU for me which decreases cycles between sensor polling (adjusts more rapidly to changing conditions/fuels) and has a few fuel map adjustments that were recommended to me after I described what I was doing. Thanks to this being an OBD2 vehicle I was able to use a scangauge to determine my existing fuel trim, which sat at + or - 3 on gasoline. I bench adjusted the fuel pressure regulator to 72psi (oem is 65) and since I already use an outboard Walbro 110psi fuel pump (half the price of replacing the in-tank assembly when it wore out) I shouldn't have any pump related issues.

I'm no master mechanic, just some dork who grew up on a farm but I have a decent understanding of the differences among these fuels, and how to work with them. It really is this easy, and my experiences exactly match what I expected: E85 has fewer btu's and is heavily oxygenated compared to gasoline, so you have to supply more of the fuel per combustion, but thanks to its higher octane and self-provided oxygen - AND the fact that you ARE injecting more fuel - it ultimately does provide a greater amount of power if for no other reason than because your air intake can't bring as much oxygen in through natural aspiration with gasoline.

Like I said, an ASE master mechanic should know this, I'm not formally educated and managed to get it.

[Swiftbow]

Originally Posted by Lazarus

... It's from the ethanol folks so take it with a grain of salt but ...

I take it with a grain of salt. I disagree with comments that avg drivers can't discern mileage difference between ethanol blend and without. I see notable decreases.

When ethanol was first being broached as a blend and oxidizer for gasoline, I thought it was a good idea to help alleviate dependence on foreign oil, help farmers and foster the local economy but as I found decreased FE and later learned about the eco problems that increased acreage of corn production causes with contaminants along with higher food prices and how the economy wasn't improved but worsened due to tax payer subsidies for corn production, my opinion on ethonated fuel has changed.

I support research in bio-production of ethanol, especially as it has proven quite viable in Brazil with sugar cane but our use of corn is a disaster; however, it is now integrated so steeply within our political system that I doubt it can be pulled.

Doug

[Allch Chcar]

Originally Posted by DeserTBoB

Then, after hearing the baloney that ETOH has a higher octane than regular gas, I switched to 87. The car barely made it to 18 MPG, as the knock detector was working overtime retarding the timing under load to prevent ping. Disconnecting the sensor yielded dangerous levels of detonation. For further runs, I switched to 92 octane, and ping is STILL a problem, which it never was before. Only by using premium E10 and jacking the basic timing up to 10° was I able to get up to 22.5 MPG average, and detonation on a dry day is a continual problem. That goes away for the most part on more humid days, proving that the fuel is the problem, not the engine.

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!

[gone-ot]

Originally Posted by Allch Chcar

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?

...are you aware of the differences between the Toyota 1ZZ, 2ZZ and 2ZR engines? The 1ZZ and 2ZR are normally aspirated while the 2ZZ is supercharged. And, although the 1ZZ and 2ZR are similiar, they have totally different fuel systems, the 2ZR uses Direct Injection Spark Ignition (DISI), not multi-port injection as the 1ZZ and 2ZZ use.

...the 2ZR engine in my '09 Vibe is neither supercharged nor turbocharged, so it cannot 'benefit' from alcohol and its higher octane number (as I stated before). And, I don't believe the Toyota/GM ECU has ever been calibrated to operate in flex-fuel mode (needs different sensors too).

...as for, "...how do you figure it lost power?"--it's simple. There's a 200-foot hill I drive at 40 mph with cruise-control engaged every afternoon going home from work...when the car had to downshift on E85, where it didn't before, that's a 'de facto' loss of power by my 'seat-of-the-pants' sliderule calculations (all else being essentially identical).

...to parody Ceaser's quote: VENI, VEDI, VICI...I saw, I tried, I dislikey!


YMMV...obviously.