Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Please note that it is not permitted to have referral links posted in your signature. Keep these links contained in the appropriate forum. Thank you.

https://www.boards.ie/discussion/2055940817/signature-rules
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

"Ethanol / E85 is very corrosive" and other myths

  • 30-05-2009 12:09am
    #1
    Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭


    Ive commented many times on Ethanol and attempted to bust some of the myths that are thrown around. In the background Ive been experimenting for the last year and can now reveal some results that maybe of use to many a hobbyist.

    Im currently converting our Audi Allroad to E85. For all intents and purposes the bulk of it is done. One thing that I frequently come up against is largely unsubstantiated claims that Ethanol is "very corrosive" and "rots rubber". Is it now....? Here is data I pulled and grouped for ease of comparison from Dupont (Internet Explorer only):

    FuelsvsMaterials.jpg

    Acetone and Toulene are Octane Boosters / Fuel Cleaners / Magic Emissions fixes Ive seen here and other forums. To say they are bad for almost any common material would be an understatement.
    The real surprise however is plain old Gasoline.. yeah, our old friend Petrol will seriously screw up Rubber, Silicone and various other parts unless specifically treated. Anyone that's ever used Petrol to clean oil, grease or tar wont be too surprised, its potent stuff.
    Ethanol is bad for certain materials for sure (and its really bad for your hands.. :o) but it isn't the killer car dissolving chemical from beyond that hearsay paints it as. Methanol is the one thats quite bad for certain metals (aluminum included), but metals arent included in the chart.


    Finally, the drastic MPG drop from burning E85?
    Its said its a straight out 30% drop, making it pointless/cost money to use over 95octane.
    Audi Allroad 2.7 BiTurbo, 152k miles, '2000 model
    - Upsolute "E5" tuned remap, 300ish BHP: Average 19.1MPG on standard E5 fuel

    - My personal Tweaked version of their Map: Average over last 2 days with 2 people, full tank of E85, AC on half the time: 19.9MPG and climbing.

    That's right, Ive scraped a slight increase combined with better performance and at ~97.9c / litre, it costs less than diesel and way less than unleaded! Ive drastically upgraded the fuel delivery capacity of the car to deliver upto over 45% more fuel yet it still performs on par with E5:
    +21% larger injectors, +25% larger FPR and uber 280lph Denso Fuel Pump wired direct to the battery for max voltage.

    The ultimate goal will be to reach my old un-remapped, stock figure (was at 250bhp) figure of 21mpg, which now seems possible as I'm not quite done tweaking. Regardless, E85 has proven it can match E5 (which already is superior to 95octane) on boosted applications and is clean enough to use without even having a Cat in the car (not confirmed personally yet, but by NCT folk).


Comments

  • Closed Accounts Posts: 7,686 ✭✭✭JHMEG


    Good post matt.

    A quick question tho: why do you need larger injectors etc if you are burning fuel at a slightly slower/very comparable rate?


  • Registered Users, Registered Users 2 Posts: 14,907 ✭✭✭✭CJhaughey


    The fact that E85 is not corrosive is true, however you need to also point out the fact that the alcohol portion of E85 will absorb moisture from the air.
    This can lead to problems with corrosion, not running E85 per se.


  • Registered Users, Registered Users 2 Posts: 1,940 ✭✭✭maxwell smart


    Matt

    My wife has a flexifuel focus, which after a reasonably unscientific trial gets around 5% less mileage on the E85. Do you reckon this is because its just a stock 1.8 with no boosting equipment? (If I'm understanding your post correctly).
    Also, maybe you have information about another myth to do with E85, does it produce less emissions? And if so what would be the result of putting a (non adjusted) car through the NCT with E85 in the tank, would the emissions be lower?


  • Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    JHMEG wrote: »
    A quick question tho: why do you need larger injectors etc if you are burning fuel at a slightly slower/very comparable rate?
    I was actually thinking about that this morning, it sounds kinda contradictory doesnt it!? What it appears is that while it does indeed burn the fuel much faster (I can log Fuel Trims and unfortunately slightly inaccurate Narrowband O2s in VagCom, but its definitely using about 30-40% more per volume), the amount of power and torque extracted from the burn however is much higher and I can adjust the ignition timing quite aggressively (as its 104octane cool burning), meaning basically you can part throttle or idle quite efficiently but getting upto that speed and WOT requires the rather big increase in fueling.
    With the larger injectors but without the bigger Fuel Pressure Regulator and Denso (some Jap love there, its from a Supra Twin Turbo!) Fuel Pump, I logged an Injector Duty Cycle peak of 90% (I was aiming for a "safe" 80% and below) at WOT. Driving at 2600rpm ish was using 0-12% IDC, which now would be lower presumably with the larger flow modifications.
    Matt
    My wife has a flexifuel focus, which after a reasonably unscientific trial gets around 5% less mileage on the E85. Do you reckon this is because its just a stock 1.8 with no boosting equipment? (If I'm understanding your post correctly).
    Also, maybe you have information about another myth to do with E85, does it produce less emissions? And if so what would be the result of putting a (non adjusted) car through the NCT with E85 in the tank, would the emissions be lower?
    Boosting equipment meaning turbo (which I what I was referring to)? Moderate+ turbo (Im only at 14psi due to an issue with the Upsolute provided remap) applications or extremely high revving, high compression NAs are pretty much the only applications that will get the type of MPG equalizations Im seeing. 5% drop in MPG with a 16% drop in Cost per litre, you are still coming up trumps!
    The emissions being lower for E85 isnt a myth thankfully, they are drastically lower, so much (in theory for now) they negate the need for a Cat in the car:
    Supercharged Miata. from E85 Vehicles forum, test on regular 95octane:
    HC:0.8765
    CO:16.2569
    NOx:0.7183
    
    Test with 25% E85 and 75% 95octane:
    HC:0.3774
    CO:8.0269
    NOx:2.0734
    
    Note the NOx went up (JHMEGs old Bugbear ;)). This is normal for low E85 concentrations, once the amount is over 33% intank NOx drops down to slightly under 95octane levels. It never however plummets like HC and CO results.
    CJhaughey wrote: »
    The fact that E85 is not corrosive is true, however you need to also point out the fact that the alcohol portion of E85 will absorb moisture from the air.
    This can lead to problems with corrosion, not running E85 per se.
    Yeah, this is true, which is why in [US ethanol/methanol] racing applications they drain the tanks between races. Leaving a car sitting for a couple of weeks with a tank full of E85 isnt a good idea (though leaving cars sitting full of fuel is never a good idea). Conversely, Ive seen people purposely use E85 to flush water contamination out of fuel tanks too! Pushing this danger to the max I changed the fuel pump in the rain.. wasnt really a very good plan but stupid weather is random!


  • Registered Users, Registered Users 2 Posts: 942 ✭✭✭gofaster_s13


    How are you finding cold starts when running E85 ??


  • Advertisement
  • Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    How are you finding cold starts when running E85 ??

    Entertaining! Without the special heating and sensing equipment of a real Flexfuel vehicle, I can really only clumsily add or subtract fuel during the Warm Up Cycle. Ive got it down to about 6seconds of constant cranking to start. It sounds like trying to start a car with no fuel in it. Ive tried adding and subtracting fuel enrichment and also increasing idle torque and idle RPM, but no silver bullet as yet. Here is the tweaking tool Im using:
    unisetting.jpg

    The first start of the day is problematic, any additional starts are fairly instant.


  • Registered Users, Registered Users 2 Posts: 942 ✭✭✭gofaster_s13


    Have you tried it in winter yet, thats entertaining:mad: havent seen anything modified to run E 85 get good cold starts yet, last car was a 2litre sr20det Nissan and was using 1200cc injectors:D and a Bosch 044 external pump and swirl, absolutly amazing torque gains:cool:


  • Closed Accounts Posts: 7,686 ✭✭✭JHMEG


    Really interesting stuff matt, keep it up.

    Now that I've been driving the IMA for a while and know how much I get to the tank I am going to up add maybe up to 20% E85 and see how I get on. Weather being warmer should help too.


  • Closed Accounts Posts: 1,467 ✭✭✭bushy...


    A coolant heater might save wear on the days in winter when you're not tweaking it ,

    http://www.canadiantire.ca/browse/product_detail.jsp?FOLDER%3C%3Efolder_id=1408474396672419&bmUID=1228881022278&PRODUCT%3C%3Eprd_id=845524443286687&assortment=primary&fromSearch=true

    nice anyway - warm air inside straight away in winter.


  • Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    JHMEG wrote: »
    Really interesting stuff matt, keep it up.
    Now that I've been driving the IMA for a while and know how much I get to the tank I am going to up add maybe up to 20% E85 and see how I get on. Weather being warmer should help too.
    Do, and update here! If anyone that tries it out updates this thread it would be real handy for future experimenters.
    bushy... wrote: »
    A coolant heater might save wear on the days in winter when you're not tweaking it ,
    http://www.canadiantire.ca/browse/product_detail.jsp?FOLDER%3C%3Efolder_id=1408474396672419&bmUID=1228881022278&PRODUCT%3C%3Eprd_id=845524443286687&assortment=primary&fromSearch=true
    nice anyway - warm air inside straight away in winter.
    Man, thats not even expensive. Will have to come back to it if cold weather proves as tricky as they say.


  • Advertisement
  • Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    How are you finding cold starts when running E85 ??

    Here is how it generally starts these days:


    Ive got it down to only a "stumble" on cold starts, though in the current weather its admittedly not very "cold". Note the video was recorded as an exhaust demo, hence the revving.
    Got 251miles to the tank (vs 260 on Petrol) today and paid 19c per litre less than petrol.


  • Registered Users, Registered Users 2 Posts: 1,525 ✭✭✭DanGerMus


    Good results there, how much has converting cost you?

    RS6 exhausts are sweet btw.


  • Registered Users, Registered Users 2 Posts: 4,407 ✭✭✭Dartz


    Funnily enough, I remember the Haynes manual for k100-series BMW's specifically saying to avoid the use of fuels containing alcohol, as it damages the cylinder bore plating.

    I also remember an article in Bike Magazine, where a 675 Triumph was converted to run on alcohol, and a big problem was the particular type of rubber hosing not reacting well to alcohol in the fuel system.

    The same again, with Top Gear and their 24 hour race. The car was crippled by damage due to excess methanol in the Fuel system.


  • Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    DanGerMus wrote: »
    Good results there, how much has converting cost you?
    RS6 exhausts are sweet btw.
    Well I already had some of the parts from my treasure trove of Audi tuning parts, but prolly around:

    - 6x Injectors: $100 (Audizine forum classifieds)
    - Denso Fuel Pump $110 (ebay)
    - FPR $40 I think (VAST Performance)

    I never pay RRP for anything, just scavenge from forums and ebay mainly, so RRP on those parts is a lot more. I could have ditched the FPR and just used even larger injectors, but I had the injectors already and they are quite a nice replacement (spray pattern, cold starts etc) for the stock injectors.
    Dartz wrote: »
    The same again, with Top Gear and their 24 hour race. The car was crippled by damage due to excess methanol in the Fuel system.
    Yeah, methanol isnt very friendly. That was a Biodiesel (while this is all petrol stuff, I previously ran my other car on Biodiesel) car btw and the Biodiesel production system they used was made by Greenfuels.co.uk. Said manufacturer was not happy with the way that went down, something along the lines of the fuel not being prepared properly and a bit of a falling out ensured due to the one sided, alarmist way it was shown on TV.


  • Closed Accounts Posts: 7,686 ✭✭✭JHMEG


    Matt Simis wrote: »
    Got 251miles to the tank (vs 260 on Petrol) today and paid 19c per litre less than petrol.
    Nice sound!

    What size is a tank, or more precisely, a fill?


  • Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    JHMEG wrote: »
    Nice sound!

    What size is a tank, or more precisely, a fill?

    Around 65Litres, so yeah, Im not exactly saving the planet no matter what way I splice the numbers! :D


  • Closed Accounts Posts: 7,686 ✭✭✭JHMEG


    Matt Simis wrote: »
    Around 65Litres, so yeah, Im not exactly saving the planet no matter what way I splice the numbers! :D

    No, you're not doing that anyway :)

    Currently getting 620 miles to a 50L tank, which is really a 45L fill, mixed driving (some lads are getting 1000 miles to a fill in the same car:eek:).

    Nearly finished this tank, so want to try 40L petrol with 5L E85 on the next fill. Oh and I have to install a warm air intake too...


  • Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    JHMEG wrote: »
    Oh and I have to install a warm air intake too...


    Lol, Warm Air Intake, a CAI without an air duct (ie sounds nice but no gain) or something more exotic Im missing?


  • Closed Accounts Posts: 7,686 ✭✭✭JHMEG


    No, the car's stock induction piping takes cold air from just behind the grille. Hypermilers etc recommended that warm air is piped from back near the exhaust manifold (which is to the back, not the front as is normal) for improved efficiency. Cold air is for power, which is not what this car is about!


  • Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    JHMEG wrote: »
    No, the car's stock induction piping takes cold air from just behind the grille. Hypermilers etc recommended that warm air is piped from back near the exhaust manifold (which is to the back, not the front as is normal) for improved efficiency. Cold air is for power, which is not what this car is about!


    Thats interesting. I know the Secondary Air Induction system on many cars works like that, though primarily used for reducing emissions, especially during cold starts. I know diehards disable it, again for power reasons though.


  • Advertisement
  • Closed Accounts Posts: 752 ✭✭✭JimmyCrackCorn!


    would you not just fully remap the car and get the full benefit.

    A vems Ecu will give you full wideband fueling and you can turn up the boost if its a turbo model.

    First start has always been an issue on any car iv seen converted.

    Go to Sxoc.com/vbb and search for e85. There are about 4-5 cars running on it, two that broke the 400bhp mark a week or two ago


  • Closed Accounts Posts: 7,686 ✭✭✭JHMEG


    Ninety9er on here has been running E85 for a good while now afaik too?


  • Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    would you not just fully remap the car and get the full benefit.

    A vems Ecu will give you full wideband fueling and you can turn up the boost if its a turbo model.

    First start has always been an issue on any car iv seen converted.

    Go to Sxoc.com/vbb and search for e85. There are about 4-5 cars running on it, two that broke the 400bhp mark a week or two ago
    Its all about cash at the moment unfortunately. Its also fun to work with what you have in your garage as opposed just buying it off the shelf. The end step will be of course to get a remap specifically extolling the virtues cool burning 104octane. Currently it has a pedestrian (and broken) 99octane map. There isnt much options in off the shelf e85 maps at the moment anyway.

    Will check out that forum link though, thanks.


  • Closed Accounts Posts: 7,686 ✭✭✭JHMEG


    Have just put in 39.5 L of regular unleaded from Tesco, which is probably E5, and 5.1 L of E85 (at 94.9c a L - woohoo!), in on top of probaby about 5 L of reserve. All in roughly 10% ethanol in there now.

    No noticeable difference in performance or starting but I don't gun it and I don't have a regular starter motor anyway. Only drove 11 miles since filling, stopping twice at the shops, so far averaging 75.4mpg.

    According to this crowd slightly better economy might be possible anyway with E20 to E30, going as high as E65 before there were problems.
    http://www.ethanol.org/news/index.php?newsid=25

    The study is here (haven't read it yet):
    http://www.ethanol.org/pdf/contentmgmt/ACE_Optimal_Ethanol_Blend_Level_Study_final_12507.pdf


  • Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    JHMEG wrote: »
    According to this crowd slightly better economy might be possible anyway with E20 to E30, going as high as E65 before there were problems.
    http://www.ethanol.org/news/index.php?newsid=25

    The study is here (haven't read it yet):
    http://www.ethanol.org/pdf/contentmgmt/ACE_Optimal_Ethanol_Blend_Level_Study_final_12507.pdf


    Somehow I missed that research in my web crawling. Cool stuff and I can attest to E30 being a sweet spot, the car felt fastest at around E30 and generally feeling faster is in the same area as best MPG.


  • Closed Accounts Posts: 3 mcloran


    I am using Hunflex converted 1.4 16V Seat Ibiza 2003 from last year.
    Starting is OK even in cold time . Cost was 300 quid and no need to cut any wires just plug in and go. Its connected to the injectors directly. The only problem here in Ireland: The price difference is 20% only comparing with petrol. The same problem with LPG as well. In mainland of Europe the difference is about 35% for E85 and 40-50% for LPG!!!:cool:


  • Closed Accounts Posts: 7,686 ✭✭✭JHMEG


    I don't understand this. I drove to Templemore and back (about 170 miles) and it's looking like my economy has improved by about 6-7%.:confused:


  • Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    JHMEG wrote: »
    I don't understand this. I drove to Templemore and back (about 170 miles) and it's looking like my economy has improved by about 6-7%.:confused:


    Already improving with only a sampler of ethanol? The cynic would say your are running lean and thats a bad thing. The optimist says thats ethanols higher efficieny at work, whats your feeling, any drivability issues?


  • Closed Accounts Posts: 7,686 ✭✭✭JHMEG


    Matt Simis wrote: »
    Already improving with only a sampler of ethanol? The cynic would say your are running lean and thats a bad thing. The optimist says thats ethanols higher efficieny at work, whats your feeling, any drivability issues?
    The cynic in me would say I'm driving more carefully as I'm looking closely at economy. But I don't think I am!

    To cut a long story short I got lost on the way and had to drive like I was in the WRC for the last 20 miles (I was on my way to a removal). But I still managed to get a slightly higher than average economy over the whole journey!

    Drivability is hard to tell. Maybe slightly more power, but also slightly more economy at lower speeds. I was looking at 110mpg driving all the way through Celbridge this evening, which isn't normal. Nothing else to report. Haven't had a cold start yet tho, but I'm only at E10 levels so I wouldn't expect any problems.


  • Advertisement
  • Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    JHMEG wrote: »
    I was looking at 110mpg driving all the way through Celbridge this evening, which isn't normal.

    What car is that again? Im impressed it has the facility to display triple digit MPG figures!


  • Closed Accounts Posts: 7,686 ✭✭✭JHMEG


    Matt Simis wrote: »
    What car is that again? Im impressed it has the facility to display triple digit MPG figures!

    04 Civic IMA. Triple digits isn't unusual. The older Vectra (and maybe the last one too) could show 999.9mpg, and often did, albeit only briefly. Mine maxes out at 150!


  • Closed Accounts Posts: 752 ✭✭✭JimmyCrackCorn!


    Yo do know your not going to get fantastic economy with E85 without a proper map.

    The piggyback boxes arnt the best and as a general rule dump 30pc extra fuel into the engine.

    By doing this you are not getting the advantage of lean cruse or adjusting the timing as the Peak cylinder pressure of the engine will change as E85 burns at a different rate to petrol.

    In summary Just dont expect massive increase in miles per euro


  • Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    Yo do know your not going to get fantastic economy with E85 without a proper map.
    The piggyback boxes arnt the best and as a general rule dump 30pc extra fuel into the engine.
    By doing this you are not getting the advantage of lean cruse or adjusting the timing as the Peak cylinder pressure of the engine will change as E85 burns at a different rate to petrol.
    In summary Just dont expect massive increase in miles per euro


    Are you aware that I dont have an E85 specific map nor do the cars in JHMEGs report and the guys on SXOC.com and they are all getting better mileage at various concentrations, despite common knowledge dictating otherwise? Did you read any of the preceding stuff?


  • Closed Accounts Posts: 752 ✭✭✭JimmyCrackCorn!


    Matt Simis wrote: »
    Are you aware that I dont have an E85 specific map nor do the cars in JHMEGs report and the guys on SXOC.com and they are all getting better mileage at various concentrations, despite common knowledge dictating otherwise? Did you read any of the preceding stuff?


    Im afraid your not making a fair comparison here. Theres a couple of factors that mean your results will be a little different.

    • The s14 runs quite a rich mixture on boost up to 11:1 to 12:1 as nissan mapped the car to be safe on 95 octane under significantly higher boost than 8psi it left the factory with
    • All the 200sx were mapped fully with timing adjustments meaning it makes full use of the fuel. (My PCP comment)
    • The maps were deliberately leaned out at cursing loads and motorway load points to improve fuel economy. (this is also done in after market chip tuning under petrol)
    Your approach by adding fuel across the board is comparatively crude. While it will work if done correctly it would be unrealistic to expect the same dramatic improvement in fuel economy.

    it is equally as untrue to say you will burn 30pc more as to say you will get dramatic reduction in mpg. Your results will vary depending on the factory map, engine compression ratios and a whole host of other factors.


    Sorry if my post was unclear I just think you have missed a couple of the key points.


  • Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    [*]The maps were deliberately leaned out at cursing loads and motorway load points to improve fuel economy. (this is also done in after market chip tuning under petrol)
    [/LIST]
    Your approach by adding fuel across the board is comparatively crude. While it will work if done correctly it would be unrealistic to expect the same dramatic improvement in fuel economy.

    it is equally as untrue to say you will burn 30pc more as to say you will get dramatic reduction in mpg. Your results will vary depending on the factory map, engine compression ratios and a whole host of other factors.

    Sorry if my post was unclear I just think you have missed a couple of the key points.

    Hey, Im not making any promises on what people will achieve, Im reporting what I have achieved, the original 30% drop brought up to +2% gain in MPG. I have dramatically decreased Fuel Enrich on Decreasing Loads, which effectively is leaning fuel on cruise while enriching it on WOT (with the inversion). I also made timing adjustments.
    Regardless, I dont know what you are singling out the SX specifically, it was just one example and neither of the participants on this thread have that car.

    As I said, this is all in the original post (admittedly the nitty details are in the link provided), yet you seem to be only commenting on info on this page of the thread, hence the question if you read the other page or not.


  • Advertisement
  • Closed Accounts Posts: 7,686 ✭✭✭JHMEG


    Just burned off the last of the 10% mix of ethanol and from what I can tell the economy was pretty much the same as on regular unleaded. The 2nd half of the tank didn't seem as economical as the first, but I'm sure that was just in my head.

    130 miles into what I am calling a 20% mix. Put 35 litres of unleaded in on the reserve and another 9 litres of E85 in on top of that.

    No huge difference so far. Economy is down slightly but that's probably due to driving up mountains that I don't normally drive up!

    Downside is the local Maxol seems to be pricing his E85 relative to unleaded: Unleaded has gone up 3c and so has his E85.:mad: Now at 97.9c a litre.


  • Registered Users, Registered Users 2 Posts: 1,980 ✭✭✭limklad


    JHMEG wrote: »
    I don't understand this. I drove to Templemore and back (about 170 miles) and it's looking like my economy has improved by about 6-7%.:confused:
    I would not expect that and I am a Fan of Ethanol. Could it be you are more aware of your driving, doing less higher rev driving and press less hard on the pedal when you want increase speed?


  • Closed Accounts Posts: 7,686 ✭✭✭JHMEG


    Yes indeed. (I did say that it was possible I was paying more attention.) I would say that my economy was overall as good with 10% as with 0% tho. 20% is hard to tell so far. I'd estimate at this point tho that fuel economy will be about the same as 0%, or maybe a fraction less.

    My aim is really to get to 30% and run a few tanks at that. So far so good: 10% and 20% have not adversely affected the car in any way.


  • Closed Accounts Posts: 7,686 ✭✭✭JHMEG


    Just filled 30.27L of unleaded (118.9c/L) and 15.01L of E85 (97.9c/L) for a ~30% mix. Driving fine so far (10 miles).

    20% was close to as good as 0%.

    Only strange thing is the fuel gauge is slower to react to having E85 put in the tank. Will take a min or 2 for it to reflect the level.


  • Closed Accounts Posts: 7,686 ✭✭✭JHMEG


    Very interesting. Minnesota State University ran an unmodified Prius on E85.

    http://www.greenenergynetwork.com/media/studies/prius-e85.PDF


  • Advertisement
  • Registered Users, Registered Users 2 Posts: 8,718 ✭✭✭Matt Simis


    JHMEG wrote: »
    Very interesting. Minnesota State University ran an unmodified Prius on E85.
    http://www.greenenergynetwork.com/media/studies/prius-e85.PDF

    Another good link.. Interesting reading, CO Emissions improvements werent as good as I was expecting, though reading in detail it appears the high CO was primarily in the Cold Start phase and much lower in the driving and idle testing. Surprisingly NOX was way down compared to Petrol, I would have thought it would come in about 33% of the petrol rating, given its not E85s strength. Hydrocarbons effectively eliminated on the rating scale they used.

    The Dyno results, on a completely untuned car throwing Lean codes were fantastic, 20% better HP and 32% higher Torque is staggering. That would quite definately feel faster. Infact its better performance, by far, compared to a performance Remap on a non-Turbo car could hope for.. and it cost nothing.


    The update I have on my testing is I had a "bad" fill of E85 (full tanks for me still) 2 wks ago. Filled up in Maxol Navan on the day they got their E85 tanks refilled (were completely empty day before). Checking Fuel Trims in VagCom over the next few days showed a massive (-14%) correction, the engine was running much richer than required and it was correcting. It would appear the petrol content in the "E85" was incorrect, I would estimate it was more like E50 (which would have run in nearly any unconverted car incidentially). If I had the car tuned to the nines it may have been a problem. Luckily the ECU was well able to correct that, I also increased the O2 Sensor scanning interval to ensure its fairly fast at reacting to this if it happens again. Strangely my (on "good" E85 again) Fuel Trims are now around -5% (ie a bit rich) under partial throttle, which in theory means I could lean it out more. However without a Wideband O2 I cannot rely on the cars O2 (Lambda) reading, so I wont be doing that just yet.

    Fairly hard driving (back to normal for me), and my MPG is stabilising at 19.2mpg vs 19.8 on Petrol. I esitmate I get 245miles to a tank vs 260 on petrol. Given the 97.9 vs 119.9 cost per litre, E85 is still working out considerably cheaper than petrol however. Feels like cheating, cost less than diesel, cleaner and better performance than petrol!


  • Closed Accounts Posts: 7,686 ✭✭✭JHMEG


    LOL! A "bad" fill has too much petrol in it! Could have been serious tho, like you said, if the car was highly tuned.

    Speaking of Wideband O2 sensors, my car is equipped with one from the factory. The ECU leans out the mix to about 25:1 when cruising, which causes a build up of NOx in the cat. Every couple of mins the ECU goes super rich for the purposes of burning off the NOx that are trapped in the cat. (Incidentally the plasma reactor in the exhaust of the i-DTEC engines works in a similar way, but to burn off heavy particlulates aswell as NOx)

    Do you know can any standard OBD-II software read the air/fuel mix from a factory wideband O2 sensor?


Advertisement