E85 - Anyone else getting great results?

[Allch Chcar]

Originally Posted by shovel

Ethanol has far fewer BTU's per pound, which is why you have to burn more of it to accomplish the same work.

But ethanol also has a higher resistance to predetonation (octane) which allows more aggressive ignition timing, and provides smoother/more even burn - as well it brings a lot of its own oxygen to the party so it increases the volumetric efficiency of the engine.

As a side note, gasoline burns most completely at its stoich. ratio of around 14.7:1 at sea level. But it releases the most BTU's per pound at around 12:1 so on paper, you should be able to return better fuel efficiency when running rich than when running lean.

This site has a DOE based (link invalid) number of 65.5% for the BTU energy content in E85. 65.5%, yet all Flexfuels get at least 70% of their gasoline fuel mileage. The power does make a difference .

This thread over at turbobricks is dedicated to converting to ethanol. Getting a flexfuel setup is still the hardest part. The guy running the guide is stating the stoich for E85 is closer to 8.6:1. He's also saying that EFI is designed to burn the fuel as close to Lamda as possible and any liquid fuel can be run if you size the injectors close enough. Anyone ever heard of such a thing being capable with EFI? I think this part about EFI is what people miss when they get stuck on the adjustability of carburetors.

[abogart]

I just started blending E85 with regular 87 E10 over the last couple tanks in my 96 non-flex-fuel car. The first tank was a blend of around 20% ethanol. MPG was only 1 MPG lower than the previous tank on reg 87, and this could have been due to other factors.

The first thing I noticed was the overall drop in mid-range horsepower, it takes more pedal now to get the same acceleration power as before on reg 87. This is great for my car because I only normally use about 35% throttle max to achieve a 75% engine load while accelerating (max load before knock sensor starts retarding timing on 87). I found that I can now run up to about 25" Hg man. press. without knock at 2500 RPM and 23" at 1500 RPM. This is a slight increase from the 24" at 2500 and 22" at 1500 running reg 87, meaning that I can use more throttle now resulting in less pumping losses, although 22" seems to be the sweet spot for acceleration.

The funny thing is that low-end torque seems to be quite improved by the ethanol blend. This might just be due to warmer weather, but it feels like I use much less pedal at cruise to maintain speed.

Scangauge reports similar or higher real-time MPG than when running reg 87 at cruise. I'm not sure if this is simply due to the way that SG calculates MPG or not, though I did have to bump up the fuel correction from about +7% to +9% for the first fillup. I have also been watching the fuel trim. Before, it ran at about -6 to -8 at cruise. With E20 it is about -3 to -4, and with E30 it runs between 0 and +6 for city driving so far. This indicates that I should be able to further increase the percentage of ethanol without compromising fuel delivery.

The only thing I really worry about is the rumored corrosiveness that ethanol supposedly has on fuel system components. I watched this video in which a couple of mechanics tore apart a non-flex-fuel vehicle that had been run on E85 and showed no signs of degradation. However this video is sponsored by a pro-ethanol organization, so I'm not sure how much credibility it actually deserves. Although I haven't yet seen any videos in which they have torn apart engines and actually FOUND premature damage from ethanol fuel.

I will be making the 180 mile trip across the state again today, and I should have some results of how the E30 performs.

[roosterk0031]

I've been playing with E85 blends recently with the Stratus, it seems that the scangage needs to be recalibrated for each blend, I started recording trips with blends and decided the numbers weren't any good, have to wait till refills IMO.

We just got a 2010 FFV Impala so just starting to get some data on it. Last tank of E85 netted 24 mpg or $0.11/mile. Would have to get 34 mpg at current E10 price to match cost wise. So far my wife gets 29 mpg mixed driving with E10. I've averaged 34 mpg with E10 on 70 mile day trip with 10 of it city.

I have a hard time worring about the corrosiveness of something if you get before the add the gas can be drunk.

[euromodder]

Originally Posted by abogart

The only thing I really worry about is the rumored corrosiveness that ethanol supposedly has on fuel system components. I watched this video in which a couple of mechanics tore apart a non-flex-fuel vehicle that had been run on E85 and showed no signs of degradation. However this video is sponsored by a pro-ethanol organization, so I'm not sure how much credibility it actually deserves.

It's not rumored corrosiveness, it's real.

Some fuel systems can take it because they are made to be ethanol resistent, others aren't and they can't take much ethanol.

[Frank Lee]

After '88, in the States, all automotive is supposedly resistant.

[gone-ot]

...aluminum and ethanol don't "play well together."

...stainless steel and ethanol, however, are OK with one another.

[abogart]

Originally Posted by Old Tele man

...aluminum and ethanol don't "play well together."

...stainless steel and ethanol, however, are OK with one another.

Ah, so it's most likely the fuel rail that I should be concerned with. I think it's aluminum, but I'll have to look at it a little closer, I don't think there's any other easy way to tell the difference between Al and SS.

What effect exactly does ethanol have on aluminum? The fuel rails seem to be a pretty sturdy chunk of metal, I couldn't really see a hole erupting in one of them simply due to higher ethanol content.

Edit: It looks like at least the outer casing is made of SS. Hopefully the rest is too.

[Frank Lee]

Did you not see my post?^ You are talking about the '96 right?

[abogart]

Originally Posted by Frank Lee

Did you not see my post?^ You are talking about the '96 right?

Yes, I did, thanks Frank . Do you have any sources to prove this? I see that many people are either way on this topic, and some good, solid evidence would be very helpful.

I also recall that in the video that I linked to above, neither of the mechanics commented on or displayed the fuel rail or injectors of the non-FFV.

[Frank Lee]

I googled it once upon a time and IIRC several reputable sources said by '88 all U.S. cars had ethanol resistant fuel systems.