Trying E85

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bulwnkl
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Trying E85

Post by bulwnkl »

I decided, based on a LONG thread in the engine mgmt. section at NABISCO, to try E85 in our Baja. There isn't E85 where I live that's available to the public, but we're on a long trip right now and there are a couple stations around.

Rather than going straight off the deep end, I started with a blend that should've amounted to 40-50% alcohol (I say should've because the amount of alcohol in E85 varies throughout the year and I don't know which blend the station I started at is running on at this time). This is a freeway trip, basically, so mpg should be pretty stable. First tank (premium gasoline, not E85) was 22.xx (I don't have my mpg log in the house right now). The last 2-3 tanks have been 22.xx as well. We have a bunch of stuff in the back and 2 bikes on the hitch, otherwise it'd be higher. First alcohol tank was 18.xx, so almost 20% mpg penalty. The E85 was much cheaper, but not enough to pay for that deficit.

Went to mid-grade gasoline from almost dead empty after the alcohol mix, and got 24.00 mpg. That was in communist Oregon, though, where speed limits are noticeably lower and we didn't have the bikes on the back. Now, I'm on straight E85 from almost dead empty. I have a CEL (w/flashing cruise control light), but I believe that's just an evaporative emission control thing. Alcohol has a different vapor pressure, so the system thinks your gas cap is loose. I'll try to get a code reader and let folks know what the code is/was, but I'm not holding my breath that I'll be able to get one today.

More updates later.
bulwnkl
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Re: Trying E85

Post by bulwnkl »

Had to abort the test early since a couple card-lock-only stations were not available to me. CEL cleared itself before I could get to a code-reader, so I really think that was a loose gas cap code (expected when running high alcohol fuel). My straight E85 tank was slightly higher than the first 40-50% alcohol tank, but again that was at lower speeds in OR. Still close to a 20% mpg penalty running alcohol.

I have found a way I could run 2 back-to-back tanks of straight E85 on the freeway, and I could even pull the battery cable off when I fill up the first time to let the ECU learn the alcohol, but I don't think I will. The alternate E85 source I have to start with is less than 5% cheaper than gasoline, so that means I'm lighting $50s on fire instead of $20s just to get home. :) IOW, I might just be too cheap to do it since I KNOW it'll cost me more.

A couple interesting observations:

1) One of the cold starts (i.e. ~52 degrees F after sitting overnight) saw a very, very poor idle. The truck also didn't want to respond to the throttle. Shut off engine, re-start after pausing with the key at "ON" position to make sure the fuel pump fully pressurized the system before starting, and the problem was gone. One other time a mild version of this happened, but cleared itself when I opened the throttle to start moving.

2) Upon startup, the truck smells a fair amount like a bottle of vodka or rubbing alcohol or something similar. This is not unexpected, I suppose, but it's kinda cool! :)
bulwnkl
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Re: Trying E85

Post by bulwnkl »

Threw one more tank through it just for fun. Straight E85 from very low fuel level. Still took a mpg hit, but the price spread was enough to make it come out slightly to the good. Only ~14% down on mpg this tank. Got the CEL again, probably for a loose fuel cap. Never anything else wrong, even at WOT in second pulling up a steep mtn. pass. So, it would appear that the Baja's ECU as well as injectors can deliver enough fuel to make E85 work OK. ...at least at 5,000 ft. Don't know what more would be needed at sea level, but I expect it'd be OK?
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Re: Trying E85

Post by corgimas »

bulwnkl wrote:2) Upon startup, the truck smells a fair amount like a bottle of vodka or rubbing alcohol or something similar. This is not unexpected, I suppose, but it's kinda cool! :)
See what the cops say....
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bulwnkl
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Re: Trying E85

Post by bulwnkl »

:lol: I thought of that!

One update: I finally got a code scanner on it and there was one stored code for System too Lean, Bank 1 (forgot the exact wording displayed). I expect that was from a very brief WOT run to redline in 2nd gear pulling up the steep section of a mtn. pass.
TheScreenSaver24
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Re: Trying E85

Post by TheScreenSaver24 »

I don't get how you used E85 in your car? I thought you had to modify the engine in order for it to work?
bulwnkl
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Re: Trying E85

Post by bulwnkl »

Well, in my case, I just pulled up to the E85 pump and filled it up. ;)

As I mentioned a post or so up, I did get a code for system too lean. IOW, one really should either put different (larger) injectors on, or raise the pressure on the fuel pressure regulator, or something. It would also be a very good idea to re-flash the ECU if you were going to do anything other than simple commuting because the alcohol will be running too lean during O/L operation (heavy acceleration, etc). During C/L, the ECU will adjust and get you where you need to be IF the injectors can flow enough fuel.

There's an excellent E85 FAQ at NABISCO in the Technical section of the forums.
Hawk296
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Re: Trying E85

Post by Hawk296 »

The problem with running E85 on a car not designed for it (like the baja) is that the fuel system is not designed for it. on flex fuel vehicles it is ok, but on the baja, the alcohol will attack the rubber fuel lines, o-rings, and speed corrosion in the metal sections of fuel line and fuel pump etc. So to run E85 all the time, you would want to replace all of those things to make sure they can handle it over time.

Then there is the fact that the ECU cannot adapt for it. It will run lean if you try to run it without re-mapping the ECU. The injectors on the turbo may be ok if you remap the ECU as they only run at about 75% max on gasoline. Keep in mind also that the air/fuel ratio for gasoline is not the same as it is for E85. while stoichiometric for gasoline is generally considered to be 14.7, for E85 it is much more rich at 9.765. The ECU is shooting for 14.7 in closed loop and up to somewhere around 10.5 in open loop for the turbo (this is still to lean for what E85 should be at in closed loop!)

I have done some experimenting on a flex fuel vehicle over the course of 1 year running nothing but E85. First off, it was a pain because there are not enough E85 stations in MI, so all fuel stops have to be planned. It actually cost more to run on E85, as the savings per gallon was not enough to offset the MPG penalty suffered from running E85. It simply does not provide the same amount of energy. Another long term effect was oil life. On oil changes (running Mobil 1 synthetic exclusively) the oil was drained and looked normal. But when running nothing but E85, the oil has a really funny color (looks like varnish) and smells really funky from the alcohol content. I cannot help but worry what that does to the engine. Even if it lubricates just as well, I still am concerned about corrosion.

All in all it IS possible to run E85 if you wanted to. You really need to change out the entire fuel system with plastics that can handle the E85 and change all aluminum and steel to stainless parts. You also must reflash the ECU to compensate. I actually was looking to do this on the baja to utilize the higher octane qualities of the E85, but my injectors are maxed out on gasoline and I do not want to go through the hassle of getting new, expensive injectors and then re-mapping everything and re-scaling the injectors.
bulwnkl
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Re: Trying E85

Post by bulwnkl »

Hawk296 wrote:The problem with running E85 on a car not designed for it (like the baja) is that the fuel system is not designed for it...the alcohol will attack the rubber fuel lines, o-rings, and speed corrosion in the metal sections of fuel line and fuel pump etc.
One of the difficult things about ethanol is that the 'information' about it varies extremely widely. For example, I was reading an article a couple weeks ago about how high-concentration ethanol fuel (like E85) exhibits far LESS fuel system attack than E10. I can't find the article just now or I'd post the link; sorry. In any event, the ~2 years of just one guy at NABISCO as well as many, many other Subie owners mainly in CO argues that E85 at least has no significant, immediate negative effects on one of our trucks.
Hawk296 wrote:Then there is the fact that the ECU cannot adapt for it. It will run lean if you try to run it without re-mapping the ECU. The injectors on the turbo may be ok if you remap the ECU as they only run at about 75% max on gasoline. Keep in mind also that the air/fuel ratio for gasoline is not the same as it is for E85. while stoichiometric for gasoline is generally considered to be 14.7, for E85 it is much more rich at 9.765. The ECU is shooting for 14.7 in closed loop and up to somewhere around 10.5 in open loop for the turbo (this is still to lean for what E85 should be at in closed loop!)
You tell me whether I mis-understand this: I understand the O2 sensor to be measuring in terms of Lambda, not AFR. Thus, in C/L operation, the system compensates perfectly for the richer fuel mixture (so long as the fuel system can flow that much fuel). O/L is a problem upon cold start for at least a moment until the ECU switches to C/L, but that super-low-load situation will not be harmful except that the lower ignitability of alcohol combined with the lean mixture will make ignition very difficult, and thus you'll wash more fuel down into the oil for a short while.
Hawk296 wrote:I have done some experimenting on a flex fuel vehicle over the course of 1 year running nothing but E85. First off, it was a pain because there are not enough E85 stations in MI, so all fuel stops have to be planned. It actually cost more to run on E85, as the savings per gallon was not enough to offset the MPG penalty suffered from running E85. It simply does not provide the same amount of energy. Another long term effect was oil life. On oil changes (running Mobil 1 synthetic exclusively) the oil was drained and looked normal. But when running nothing but E85, the oil has a really funny color (looks like varnish) and smells really funky from the alcohol content. I cannot help but worry what that does to the engine. Even if it lubricates just as well, I still am concerned about corrosion.

All in all it IS possible to run E85 if you wanted to. You really need to change out the entire fuel system with plastics that can handle the E85 and change all aluminum and steel to stainless parts. You also must reflash the ECU to compensate. I actually was looking to do this on the baja to utilize the higher octane qualities of the E85, but my injectors are maxed out on gasoline and I do not want to go through the hassle of getting new, expensive injectors and then re-mapping everything and re-scaling the injectors.
Well, you may or may not have to change injectors. Simply raising fuel pressure will give you more flow, and given the oversize capacity of the Baja turbo injectors in the first place, that will almost certainly be enough for a stock engine. I agree that a re-flash would be needed so that things don't go way wrong during O/L operation. There are tuners at least in CO that have OTS maps for E85. I don't know whether any of them would deal with a person remotely on one. One would have to be a commuter and very careful if one did not get a re-flash.

In terms of oil, I'm only aware of Chrysler still requiring anything other than plain-Jane oil for their FFVs. I run analysis on mine, and I use a sophisticated service to 'read' the analyses. I'll bet you my guy can 'see' the E85 use, but I'll post if anything bad shows up.

I agree that pricing is key. In the midwest and Colorado, E85 is enough less expensive to make it cost effective to run with the engine un-tuned. The tanks I ran were close to break-even, but there isn't much E85 infrastructure and basically no competition where I was. One thing I don't like is the reduced range of a tank of fuel. With a properly tuned ECU, you should be able to realize a lower mpg spread. If E85 becomes ubiquitous, one could easily bump compression up such that mpg would be the same or higher than gasoline mpg.
Toybox06
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Re: Trying E85

Post by Toybox06 »

The end lol
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mike-tracy
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Re: Trying E85

Post by mike-tracy »

Lots of Subarus get tuned for e85. I'm 20 miles each direction from a ethanol station (and not a direction I head for work or anything), or I'd get my turbo tuned for 0-85% ethanol.
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