E85 - Anyone else getting great results?
 

In my case I'm beating the EPA E85 mileage estimate by 31.5% and the EPA gasoline mileage estimate by 5% (when burning E85). The cost of E85 is ~20% less than gasoline, so I'm really getting 26mpg cost-wise, which beats the EPA gasoline estimate by 30%.

I would think E85 use and this forum would go together well, since not only is E85 cheaper, but all the techniques of warm intake air, advanced timing, and lean mixures would work well with E85 since it's 105 octane and detonation is much less of an issue at lean mixures/advanced timing. All I've done is installed larger injectors and changed my driving habits. With some engine/intake/ignition mods, I would think my mileage would go up even more.

Anyone else using E85? Any key mods for E85 fuel efficiency?

What was your mileage using E0?

I use it frequently, and in different strengths while mixed with regular.

Weaker than 50/50 E85/Regular leads to no driveability issues and basically unchanged FE.

Stronger mixtures can lead to harder starting and stumbling under certain conditions, mainly having to do with cold temps. In my experience, nothing too serious happens until about 10 deg F or less.

Using E0 (100% gas) I got 25 at the best when driving real carefully. That's 25% better than the EPA "combined" estimate, and 1mpg better than the highway rating. My driving is generally 50/50 city/hwy. So essentially I'm barely breaking even using E85 compared to using 100% gas. I'm just wondering if there's more potential in fuel economy mods using E85 versus gas. I know that if you significantly increase the compression ratio you can get just as good mileage as you can with gas, the problem being that you'd never be able to use gas in the car again. But I figure E85 will like cam and ignition advance more than gas, just gotta find the time to try it out.

Good to hear about your results. E85 usage is still pretty rare. There's still too much resistance to it!

I'd use the comparison of 65.5% in energy content compared to Gasoline. 70% is a good baseline for telling if you're getting good performance.

Please keep us updated.

Frank, curious about how you do the E85 thing. Say when you're at a half tank, you fill with E85? Then the next half tank do regular? And so on? I drive a 96 Grand Cherokee 4.0 that loves drinking lots of fuel. 17mpg on a good day. I'd like to see how it swallows the E85/Regular blend. What's your thoughts?

It depends on when I go fill up. I usually try to run it down pretty close to E before stopping at a gas station, but sometimes if price and opportunity are there, I'll top off sooner. So... usually I am filling a nearly empty tank. If it's above 10F or so and the forecast is for that or warmer, I'll either top it off with E85 or go 50/50. The warmer it is out, the more I tend to go with straight E85.

My town now has new "blended pumps" which allow you to select 4 different blends of E85 and regular. I haven't used it yet, and I want to go get prices from it and figure out if I'm paying a premium for that convenience or not, before I tank up.

Well you are still getting some below freezing weather and you haven't played with it at all yet, right? So if you are at 1/2 tank go ahead and top it off with E85. Or if you are near empty, blend them right there at the pumps. Just go 50/50 for a while and see how your rig likes it. If all is well, then over time I'd say you could go 75/25, see how it goes, maybe sometime this spring try a full tank if you are up to it and your vehicle has been agreeable to it so far.

I've done it with 4 vehicles, all Fords, and they all responded well. I don't have experience with other makes of cars. I tried pure E85 in my motorcycle once (carbureted) and it did NOT like it one bit. Of course the carb is not set up to compensate for lean mixtures like EFI can do. I did make it home on the bike, however, by pulling the choke a lil bit.

Would you please give more details, Frank - models, years & engines.
Thanks.

'94 F150 5.0
'93 Tempo 2.3
'92 Tempo 2.3
'92 Topaz 2.3

I've also put a blend in an '84 Tempo carbureted, but have not worked up to strong blend/straight E85 in that one. Besides, that one is old enough to where the rubber parts might have E85 incompatability and I don't feel like replacing parts on it.

EFI is your friend.

Yes, and it seems Tempos are my friends too. I can't help it! They find me and follow me home!

Thanks Frank! I'm going to start the blend after it warms up a bit. I'm still in the process of cleaning up the 1ft+ snow that fell last night. Pretty high quality snowman snow! ugh!

Thanks, Frank. If ever E85 becomes an option here, I'll give different blends a try.

I run blends of E85 in my 01 Blazer 4.3, basically anything up to about E50 in ratio runs AWESOME, acceleration is notably smoother, enough that when my GF borrowed it while it was "drunk" on ethanol she said "your car is way faster than normal, did you do something to it?"

But the engine is unmodified - apart from a high-flow intake tract/filter which serve to increase the "problem" with running E85 in a non-flex-fuel vehicle - a/f ratio. I get about 15% worse fuel efficiency, MPG-wise on a 50/50 blend of E85/straight gas.

I keep wanting to get a FullFlex system but I just don't feel confident enough in that particular company's method - it seems an awful lot like a guess to me.

I haven't come across any E85 around here, but sometimes I come across E10 while traveling. I've had noticeable increases in FE when using E10 gasoline (see fuel log); I think my record trip was using E10.

Shovel, you're saying that you get better power, but less FE running the blend?

Yep, precisely that and significantly enough that neither effect can be attributed to just being in my head.

Scangauge confirms the reduced fuel efficiency (both in measured FE and indicated fuel trim) and non-gearhead-girlfriend's "holy crap it's faster" confirms increased power ;)

If I run more than about E50 (as in, top up on E85 while I've got a third of a tank of straight gas) the CEL illuminates because fuel trim goes out of range (+25%) - which is expected. As stated, this is on an unmodified vehicle. Vortec 4.3's use a unique "spider" injector setup so it's not so easy to just step up to higher flow injectors. I do think mine might need a good cleaning, however, as base fuel trim on straight gas is still +13ish on average.... with brand new o2 sensors. :thumbup:

There are a few e85 pumps around here, but I never used them because I thought my car would run bad with it.

It seems logical that with more power one should get better FE if my driving habits are adjusted accordingly. But, the scan gauge doesn't lie, I guess. I'm going to wait until I see sustained 50 degree temps to begin my experiment with E85. I'll keep you posted as how my 1996 4.0 Jeep likes the stuff. Thanks.

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. :thumbup:

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 :thumbup:.

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.

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.

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.

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.

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

...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. :thumbup:

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

Yes, I did, thanks Frank :thumbup:. 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.

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

I grew up in central Nebraska and we have a pretty decent e85 availibility here. Some vehicles drink the stuff up, and even with the loss of mileage you can more than break even. Other vehicles seem to hate the stuff. Most EFI vehicles run e10-e20 just fine, with a small drop in FE. With the cost differential every vehicle I have more then breaks even.

If you tune for power, E85 can be your friend. Cheap, high octane, and available virtually everywhere in the midwest. You'll find alot of guys tuning for it around here.

Fortunately, if the price spread is large enough for it to be worth trying, I should be safe to give E85 a shot in the Jeep. Fuel rails are steel (not stainless), and AFAIK, there's no aluminum anywhere in the system, and the gaskets should all be ethanol compatible (and E10 certainly hasn't been an issue). Not sure how it would do for mpg without more compression though, as it's only 9.1:1, and the timing is already pretty cranked (needs 91 octane minimum).

The late, great John Lingenfelter did some work on high performance Chevy engines running on both straight ethanol (actually denatured alcohol) and E85.

He took a LS7 engine (7.0 liters 505 HP from GM) and modified it for alcohol. Obviously he jacked the compression up to 14:1 and advanced the ignition timing a bunch, but he also addressed the power loss by installing bigger fuel lines, pumps, and injectors. Result: 800 HP and he claimed the thing was more fuel efficient on a HP/MMBtu heat input basis. I’m sure he had no corrosion issues.

I would believe the increased efficiency at a very high compression ratio.

John Lingenfelter is dead, but his company still modifies Chevy engines. They might (for a price) work up an alky engine for you.

Maybe the best approach for a high-MPG alky engine is a very small engine with insane compression and/or turbo boost, but to keep the driving characteristics good, you gotta have a bigger injection system.

To burn alky efficiently, you have to sacrifice the dual-fuel capability. I’d also recommend a big fuel tank because you don’t know where the next E85 pump is.

Agreed on needing to give up dual fuel capability to get good mileage on E85. The only way to avoid that would be instead of high comp NA, go mid-comp turbo with advanced timing, and cut the boost way back on E0 or E10. Unfortunately, I can't build the Jeep for E85 only, as it's not available at home.

The results are in: 33.5 MPG on E30 up from 33.2 MPG on E20 :confused:. Note that I did increase tire pressure 40 to 45 PSI during this time and the weather has been warmer. I did have to adjust the SG fuel% up a few more points again, thinking this might affect trip MPG readings.

Knock retard kicks in at about 26" MAP. at 2500 RPM and 24" at 1500 RPM TC locked. Fuel trim ran +4 at cruise and up to +6 city. Mid-range horsepower is diminished under normal load, but still manageable for reasonably good acceleration without tripping the knock sensor, however low-end torque is even better than on E20. I actually found it difficult to cruise above the 12.4" MAP where the TC unlocks, cruise control just pulses between locked and unlocked. Cruise throttle is only 8% relative TPS, so some VERY fine footwork is required to maintain steady-state cruise.

I just put an E40 blend in the tank last night. I could immediately tell that mid-range power is reduced even more during acceleration between 2000 and 2600 RPM. Low-end torque seems even better than before. I was able to run up to 29" MAP (100% load) without tripping the knock sensor :thumbup:. Still not sure if BSFC is better in this range though. Fuel trim ran +7 city, I haven't seen it go higher than that yet, hopefully this is just because the AFR is right and not because it can't adjust any higher.

One thing that I have noticed is that I can cruise at idle for quite a ways with the trans. in D now. I'm wondering if this has anything to do with the fact that I just cleaned out the EGR passage in the intake. Another theory that I have been tossing around is that the extra vapors from the ethanol in the tank are being collected in the EVAP canister and released during deceleration. This might explain why fuel trim drops to -4 or even less during deceleration in-gear, most likely signifying EVAP purge operation.

I have also noticed that the car starts and runs a lot smoother on higher ethanol blends than on regular gasoline. I will post when I get the results from the E40 tank. Not sure if straight E85 is going to work in this car, but these blends have some seriously promising results. :D

Cars sold, or made in the US? I know for a fact that my 92 Eclipse and Talon had aluminum rails. I believe they continued it into the 2nd generation cars in late 90's as well.
Could it cause corrosion in the intake and cylinder heads as well? What about aluminum pistons?

Never heard of problems aft of the fuel system.

Got results from the E40 tank. Fuel trim running +3 at cruise, up to +10 city. I can run up to 29.9" MAP at 2500 RPM and 27" at 1500 RPM, although 22" is still the sweet spot. MPG is the same or better than on regular fuel. SG fuel% was dead-on this time, didn't need to adjust.

Had to refill with midgrade 89 E10 because I cut the return trip a little too close with this tank. This brings the tank E% to 24%. Strangely enough, the return trip reported worse MPG with a tailwind. Not sure if this is just because SG has been calibrated to the increasing E% in the fuel, but I did notice higher MAP required to maintain cruising speed on E24 than on E40. Interesting...

If they used bare aluminum than Mitsu/Chrysler would have been fools. Aluminum needs to be coated with zinc to protect against corrosion.
Stainless steel is better than steel but it gives up strength for corrosion resistance. Plastic is better IMHO than metal for the fuel system but it has to be a certain range of polymers like viton not nylon.

There have been recalls on vehicles for not being E10 compliant. The only ones I remember for newer cars were VW and Lexus. I've heard a rumor that Ford changed over the entire fuel system to be compatible with higher Ethanol blends in '94.

I've heard of people saying that engine parts would fail but I think it would have to be an old engine with lead era valveseats.

And @ everyone just to clarify all alcohols are corrosive. Ethanol is less corrosive than Methanol. They both have oxygen which is corrosive but it also helps improves power and efficiency (which is not the same as MPG that is directly related to energy density).

The Compression ratio doesn't need to be higher for alcohol to be efficient. That is just a rumor. Ethanol can run efficiently at higher compression ratios than Gasoline but it is not necessary to be more % efficient. If you want dual fuel ability I'd keep the engine as stock as possible and get a tuner for it with several tunes for different blends.

And be careful adding Ethanol or too much too fast, I'd hate to hear you blew your engine because your engine leaned out and broke something :eek:. Adequate fuel is a big concern when you're decreasing energy density that much.