Whats the difference running E98 over E85?

[black97spyder]

I have a local gas station about 25 minutes from my house and they offer both E85 and E98. What would be a better to run and What are the advantages and disadvantages of both?

All input would be much appreciated!

 

[Cdc1221]

Id say e98 will make a car extremely hard to start cold

 

[hotrodssnova]

13% LESS gasoline. If you can tune your 120 second start up on the super rich side when its cold, you should be ok.

 

[boost97gst]

More timing, more boost, more power w e98. But i would also think the globals would need to be dropped even further. You could also potentially run it a bit leaner too. I have never seen an e98 pump around here and we have quite a few.
In this weather like cdc said, if cold starts are an issue just go with e85 and maybe try the e98 when it warms?

 

[c2ypt1c]

More timing, more boost, more power w e98

Not necessarily. Just because you can advance timing doesn't always mean you should. E85, with it's "anti-knock" properties, can allow timing to be pushed past MBT without knocking. Unless you're fighting to keep knock down (due to high IATs, etc), e98 doesn't really have an advantage over e85...just my two cents.

 

[hotrodssnova]

Actually, globals would stay the same, your injector cc would drop, by at least 10%, mpg would take a hit, and you would likely have to redo your fuel map. If you have a way of running duel fuel maps, do it.

 

[black97spyder]

Thanks guys! I didn't even think about it being harder to start when It's cold ... As for the power and tuning would go, What all would be needed? Also, What are globals? I'm kind of a newb when it comes to tuning these newer computer controlled cars.

I'm interested in the pro's and con's of both.

 

[boost97gst]

Globals are what you get after you plug in the size of your injectors. Lets say you are running pump gas, 43psi, with 1000cc injectors(that actually test at 1000 ). Pop those numbers in and it will spit out something like -53% or thereabouts, its just an example. So with e85 you would take those same injectors and tell the ecu they are actually more like 660cc's(rough estimate guys, dont get too technical until you actually look at the sheet). This will give you a global of lets say.... -40%.
Now one step further and say you want e98, well you have to tell the ecu youre running even SMALLER injectors. Lets just take a guess and say you have to call those inj's 600cc's now. Global goes to -35%


All are simple examples, just guesstimates meant to prove a point. This is how it works in link v3


And true, some people do run too much timing on eth just cause they can. It becomes bad at a certain point even though youre not knocking, it can cost you power.

 

[phunny]

Cold start is an easy fix, e98 is superior in every way. Best part would be it's consistency, no more guessing what blend you have and always adjusting your globals. I will be switching over to e98 soon and I can't wait. You will also require a little more fuel than e85 so be ready for that.

 

[elocneas]

E98 would be great. You would use more fuel and would def want to take a look at your power goals and what size injectors you would need to run.

 

[4g63t]

I would not bother unless you race the car often. I think it's impractical for a dd car. Cold starting on 2% of gasoline does not sound fun when most of us have a hard time with 30% (E-70) winter blend. I can foul out plugs pretty easy with e85 when the car does not pop off right away (low battery or some other issue) I can't imagine how easy it would be to do with e98.