Is E85 killing my engine and mpg?

[Allch Chcar]

Originally Posted by euromodder

...In order to use E85, the ECU should be able to compensate for it, and the valves / valveseals should be hardened to withstand the higher burning temperatures and lack of lubing - you basically get the same valve-issues as with LPG...

The average EFI car can run upto 50% Ethanol before getting a CEL(Check Engine Light) from an out of spec condition depending on how much range the ECU is given. EFI can compensate for the differences in fueling in most driving since it usually fuels by Oxygen/Lamda Sensor which reads Stoich as 1.0 regardless of the fuel.

Gasoline engines have been using hardened valveseals since the 60's shortly after lead was banned in all pump Gasoline. Lead actually provided the lubrication for valve seals/stems, from my understanding, so hardened valve seals needed to be adopted to keep cars running without it.

If there is any merit to a concern about lubrication I haven't heard of any facts. Considering 2 stroke engines ran reliably with a mixture of 50:1 Gasoline:Oil and 2% of E98 is always an Oil based denaturant and is mixed with at least 15% Gasoline in E85 there doesn't seem to be any lack of Oil for lubrication with E85.

An another note if you noticed only 4 MPG difference from 37 MPG then it was probably your mods and driving changes more than anything else. E85 cannot affect your MPG if you aren't filling up with it .

[honestabe]

E85 is more like a race gas. I'd use it in my Supra if I were wanting to really make some power without having to spend $10-20/gallon. If you use E85, you will need to increase your fuel system's ability. To use E85 you need to increase your fuel flow rate by 20%, meaning you get much worse MPG than with regular gas.

[NHRABill]

I have not seen an E85 in the entire state where I live and only a few times in travels to other areas. The only concern I have ever heard regarding E85 is that it dries the gaskets and causes them to leak.

That was more concern from a friend that is a mechanic and responsible for ambulances in Indiana they converted a few over and we were talking about beneits from cork to pressed paper or liquid gaskets not knowing anything about E85 I was surprised by his findings I guess newer vehicles equipped to handle the fuel have the proper gaskets to resist such issues as he was having. All stations selling normal fuel are badged with 10% ethanol labels for at least 4 years now

[Frank Lee]

Originally Posted by honestabe

E85 is more like a race gas. I'd use it in my Supra if I were wanting to really make some power without having to spend $10-20/gallon. If you use E85, you will need to increase your fuel system's ability. To use E85 you need to increase your fuel flow rate by 20%, meaning you get much worse MPG than with regular gas.

^not

[Allch Chcar]

Originally Posted by honestabe

E85 is more like a race gas. I'd use it in my Supra if I were wanting to really make some power without having to spend $10-20/gallon. If you use E85, you will need to increase your fuel system's ability. To use E85 you need to increase your fuel flow rate by 20%, meaning you get much worse MPG than with regular gas.

Increasing the flow rate by %%% does not mean the MPG goes down %%%. Driving style mixed with the tune determine the final MPG. If you leaned out the tune at cruising RPM you could get better MPG but couldn't you do the same for RG Gasoline too?

Due to hanging out on Honda-tech where quite a few E85 tuning discussion goes on, I know the number is not flat across the board. One particular tuner, who's name I have forgotten, noticed that E85 on one particular engine only needed 10% or so more fuel in the low RPM vs closer to 50% for high RPM WOT. Setting it to +33%(IE) across the board ruined performance or so I recall from memory. The numbers are not exact, but you should get the idea, the amount of fuel needed depends on many variables and needs to be tuned accordingly. Each engine is different and E85 has several grades.

So please don't go throwing around numbers like that. eg saying E85 needs this much more fuel etc. The amoun of fuel is very dependent on the engine, weather, and % of Ethanol. Not to mention how the tuner decides to go, they might lean it out during cruise, put everything to stoich for a DD, or even enrichen the mixture to add more power. I've seen far too many throw numbers anywhere from 20% to 2x the fuel, all of it is bogus. Anyone who claims to know the number and to know it all for a fact is a fool. There could be a range but even that is guess work. The number people are often referring to is the difference between "pure Gasoline's" Stoichiometry and Ethanol's which is approx 42% more fuel for Ethanol over the old "pure Gasoline" w/o ethanol. But every engine is different and the number would almost never be 42%.

This is Ecomodder, more facts less feces.

[euromodder]

Originally Posted by Allch Chcar

The average EFI car can run upto 50% Ethanol before getting a CEL(Check Engine Light) from an out of spec condition depending on how much range the ECU is given.

It will compensate to some extent, but that doesn't necessarily mean it'll run most efficiently while compensating for the ethanol in the fuel.

Gasoline engines have been using hardened valveseals since the 60's shortly after lead was banned in all pump Gasoline.

Obviously not always enough to be running E85 or LPG.
While some engines are perfectly happy to run on LPG or ethanol, that certainly doesn't apply to all engines.

[PaleMelanesian]

It's instructive to look at the EPA ratings for flex-fuel vehicles. They have ratings for both gas and E85. The e85 ratings are on average 30% lower than the gas ratings.