Running e85 on lower compression engines

Bmw doubles · 10-02-2015, 01:24 PM

Interesting to see an engine with lower compression than our motors run 85% ethanol for 105k miles. A 105k!

Basically the corrosiveness claims are opposite of what were being told. They did mention fuel delivery read a little lean, but nothing alarming.

FSociety · 12-22-2015, 08:12 PM

This interesting .. maybe they dont want us using e85 because they want use to keep pumping 91/93 octane for more of their business?

Bmw doubles · 12-25-2015, 11:59 AM

Ok don't run high amounts of e85. I ran 10 gallons and got misfires. Nothing the icarly bmw app couldn't fix and putting some more 91oct in. So far I've been able to run about 6 gallons of it with no issues and better performance. 10 there was no additional gains and there was errors.

SeeYa · 12-25-2015, 09:07 PM

My problem with ethanol is that it is spectacularly bad public policy, regardless of what it does or doesn't do to an engine.

dadysev · 12-27-2015, 11:27 AM

Put ethanol to sit in a jar for a couple weeks, and look at it after. My local small engine repair shop showed me.
Basically if you are leaving it to sit in a tank for extended time, like lawnmowers, weedwackers, snowblowers, etc. it can harm your fuel system. Starts to eat out the hoses, lines, rubbers, etc. But for use in a car when you burn it off quicker you are fine.
Personally in my old e46 i got 300k miles out of it and was still going before i sold it and never experimented with anything lower than 91.
Lower Octane burns quicker (pre detonates at lower compression) hence the ping/knocking and your DME is going to constantly compensate. you will get less milage for a cheaper price. Just my 2 cents.

FSociety · 01-18-2016, 11:36 PM

Stubok e46m3lol tried E85 (3 gallons) on your N20 yet?

Stubok · 01-19-2016, 12:28 AM

Yea I have. Tried about 3 gallons in a tank. This was about the time I discovered the S55 plugs trick. So I have no comparison to running on the old stock plugs. I think I found that it ran a little better, but not a huge amount.

I think it helps much more if your running 91 or worse octane, at higher boost and have stock hot plugs, as both things can instigate predetonation and together it's a certainty. Oh and add hot IAT's and it's a perfect storm! Since I'm on 93 and have colder plugs I don't think it helped me as much, at least in making the engine run smoother. Perhaps brought a little more power, but not sure if it was that noticeable. Be great if someone could verify by Dyno.

Honestly I was scared I might blow my engine since E85 had been involved in all the talk on blown motors (Actually I think it was a timing/preignition issue with 91 and aggressive tunes/boost, But that's just my 2 cents), so I didn't push it very hard and I didn't try it after that.

Really in theory it should lesson predetonation, but supposedly the DME will also advance timing once it detects higher octane. So presumably if you constantly alternate between 91 and E85 mix and then higher boost you are asking for problems.

I believe this is one of the inherent problems of spraying meth (pretty much race gas octane) If you don't have a failsafe that backs off your timing and boost when the meth stops you will be running your engine in way too high boost and far too advanced for 93 (even worse with 91) that it will probably just go pop.

I may have to try it again and give it a better go.

10-02-2015, 01:24 PM	#1
Bmw doubles Dream crusher 984 Rep 2,421 Posts Drives: Fast Join Date: Mar 2015 Location: westside iTrader: (0) Garage List 2011 535 [0.00]	Running e85 on lower compression engines Interesting to see an engine with lower compression than our motors run 85% ethanol for 105k miles. A 105k! Basically the corrosiveness claims are opposite of what were being told. They did mention fuel delivery read a little lean, but nothing alarming. __________________ 535i MIssion Performance, PS2, Helix HPFP Kit, Wagner FMIC, Spec 3 clutch, Steel SMF, Wolf Racing CP, UUC SSK, GFB dv, SprintBooster, Custom Dynomax Exhaust, M5 Sways, Eibach OE Springs, Koni Sports Adjustable, Custom Short Ram CAI IG: @bmwdoubles
	Appreciate 0 Tweet Quote

12-22-2015, 08:12 PM	#2
FSociety IG @bmwF9xG80 3812 Rep 7,593 Posts Drives: G80 M3, X4M, G07 X7m50 Join Date: Apr 2012 Location: NYC to NJ to Orlando FL iTrader: (3) Garage List 2023 BMW G80 M3 [0.00] 2020 BMW X4MC [0.00] 16' BMW X4 M40i [10.00] 06 Cadillac STS [0.00]	This interesting .. maybe they dont want us using e85 because they want use to keep pumping 91/93 octane for more of their business? __________________ 60-130mph 6.5s X4M #HCP 60-130mph 5.0s G80 M3 #OrlandoAutowerks Sauce IG: @bmwF9XG80
	Appreciate 0 Quote

12-25-2015, 11:59 AM	#3
Bmw doubles Dream crusher 984 Rep 2,421 Posts Drives: Fast Join Date: Mar 2015 Location: westside iTrader: (0) Garage List 2011 535 [0.00]	Ok don't run high amounts of e85. I ran 10 gallons and got misfires. Nothing the icarly bmw app couldn't fix and putting some more 91oct in. So far I've been able to run about 6 gallons of it with no issues and better performance. 10 there was no additional gains and there was errors. __________________ 535i MIssion Performance, PS2, Helix HPFP Kit, Wagner FMIC, Spec 3 clutch, Steel SMF, Wolf Racing CP, UUC SSK, GFB dv, SprintBooster, Custom Dynomax Exhaust, M5 Sways, Eibach OE Springs, Koni Sports Adjustable, Custom Short Ram CAI IG: @bmwdoubles
	Appreciate 1 Quote

12-25-2015, 09:07 PM	#4
SeeYa Private 17 Rep 57 Posts Drives: 2019 X6 35i Join Date: Dec 2015 Location: Michigan iTrader: (0)	My problem with ethanol is that it is spectacularly bad public policy, regardless of what it does or doesn't do to an engine.
	Appreciate 1 Quote

12-27-2015, 11:27 AM	#5
dadysev Captain 169 Rep 687 Posts Drives: Man Join Date: Jul 2013 Location: Toronto, Canada iTrader: (0)	Put ethanol to sit in a jar for a couple weeks, and look at it after. My local small engine repair shop showed me. Basically if you are leaving it to sit in a tank for extended time, like lawnmowers, weedwackers, snowblowers, etc. it can harm your fuel system. Starts to eat out the hoses, lines, rubbers, etc. But for use in a car when you burn it off quicker you are fine. Personally in my old e46 i got 300k miles out of it and was still going before i sold it and never experimented with anything lower than 91. Lower Octane burns quicker (pre detonates at lower compression) hence the ping/knocking and your DME is going to constantly compensate. you will get less milage for a cheaper price. Just my 2 cents.
	Appreciate 0 Quote

01-18-2016, 11:36 PM	#6
FSociety IG @bmwF9xG80 3812 Rep 7,593 Posts Drives: G80 M3, X4M, G07 X7m50 Join Date: Apr 2012 Location: NYC to NJ to Orlando FL iTrader: (3) Garage List 2023 BMW G80 M3 [0.00] 2020 BMW X4MC [0.00] 16' BMW X4 M40i [10.00] 06 Cadillac STS [0.00]	Stubok e46m3lol tried E85 (3 gallons) on your N20 yet? __________________ 60-130mph 6.5s X4M #HCP 60-130mph 5.0s G80 M3 #OrlandoAutowerks Sauce IG: @bmwF9XG80
	Appreciate 0 Quote

01-19-2016, 12:28 AM	#7
Stubok Lieutenant 472 Rep 577 Posts Drives: Melbourne Red F30 328i M Sport Join Date: Dec 2014 Location: Austin TX iTrader: (0)	Yea I have. Tried about 3 gallons in a tank. This was about the time I discovered the S55 plugs trick. So I have no comparison to running on the old stock plugs. I think I found that it ran a little better, but not a huge amount. I think it helps much more if your running 91 or worse octane, at higher boost and have stock hot plugs, as both things can instigate predetonation and together it's a certainty. Oh and add hot IAT's and it's a perfect storm! Since I'm on 93 and have colder plugs I don't think it helped me as much, at least in making the engine run smoother. Perhaps brought a little more power, but not sure if it was that noticeable. Be great if someone could verify by Dyno. Honestly I was scared I might blow my engine since E85 had been involved in all the talk on blown motors (Actually I think it was a timing/preignition issue with 91 and aggressive tunes/boost, But that's just my 2 cents), so I didn't push it very hard and I didn't try it after that. Really in theory it should lesson predetonation, but supposedly the DME will also advance timing once it detects higher octane. So presumably if you constantly alternate between 91 and E85 mix and then higher boost you are asking for problems. I believe this is one of the inherent problems of spraying meth (pretty much race gas octane) If you don't have a failsafe that backs off your timing and boost when the meth stops you will be running your engine in way too high boost and far too advanced for 93 (even worse with 91) that it will probably just go pop. I may have to try it again and give it a better go.
	Appreciate 1 Quote