"Ethanol / E85 is very corrosive" and other myths

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!

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

Matt Simis

JimmyCrackCorn! wrote: »

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?

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.

Matt Simis

JimmyCrackCorn! wrote: »

[*]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.

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.

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%.

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?

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.

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.

JHMEG

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

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

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!

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?