E-85 More than just a fuel

[Dragu1a]

i put 3 gallons in my old buick rendezvous today, then topped it off with regular 87. i don't know if it was just my imagination, but the car felt noticeably smoother on my way to work.

 

[9BABCobra8]

since 85 needs a much richer stoich, you are running super lean by doing that. as long as you stay part throttle you will be fine, but things might get hot going that lean under full throttle.

does over lean gas / 85 blend melt pistons? hmm.. i'm thinking yes.

Actually ethanol and gasoline have the same lambda (1.0). When the computer reads 14.7 as your AFR it is actually reading the lambda of 1.0. Unless, you adjust the AFR read-out it will still read the AFR for ethanol at 10.0.

 

[KrisR]

Actually ethanol and gasoline have the same lambda (1.0). When the computer reads 14.7 as your AFR it is actually reading the lambda of 1.0. Unless, you adjust the AFR read-out it will still read the AFR for ethanol at 10.0.

I will add to this if I may. Most cars read the 02s to get the lambda at part throttle/cruise/idle (closed loop) only. As soon as you go into WOT it goes into open loop and relies on fuel tables that are preset and don't add in the extra fuel required for extra ethanol in e85 mixes, so you will run slightly leaner at WOT but fuel trims will correct the mixture in closed loop.

In some newer cars like my 2011 Coyote, the car is always in closed loop and lambda is monitored even at WOT, and fuel trims adjust for it and maintain the commanded lambda at all times. I have run a few gallons (3 in the first tank and 5 in the second) of e85 in my tank as an experiment in the last week or so, and the car runs much better overall and has 3-4 degrees less knock retard than it did on 92 pump gas.

 

[Goon Slider]

I ran ~50/50 mix in my B18C civic just to see if it would do anything.

I noticed it had alot smoother idle and crusing down the highway was really smooth.
I did do a wot pull and it felt better than on 91 only but the car runs rich as it is, I'm sure it just leaned it out a bit which helped ever so slightly. haha

I did try 100% E85 just because no F**ks given. haha
It idled a little rough but cruising on the highway never changed.
It would start going pretty lean if i took the rpms up to about 4k at part throttle (merging onto the highway) but under that rpm it ran good.