3.6L Pentastar running ethanol?

JK_Bbargers

New member
So I'm very curious here. I've heard of others filling their JK's with ethanol that have the 3.6L. Not sure if they had an ethanol prepped motor and what not but my question is can this be safely done? I personally have a 2014 and have never tried it. Just curious really!
 

2nd.gunman

Caught the Bug
What are we talking E10, E85? I've run E10 before in a pinch and didn't notice any difference. I'm pretty sure E85 would be a bad idea
 

RockyJk

Active Member
E-85 has ~85% ethanol in it if a vehicle is not equipped for it the ethanol will eat away the fuel lines. Flex fuel vehicles have upgraded fuel lines to handle the E-85 (stainless steel lines I believe). Most vehicles also get less mpg running It
 

13_gecko_rubi

Caught the Bug
Your engine is e85 compliant, the same one is used in many other chrysler vehicles that are flex fuel. But your tune AND your fuel system are not e85 compliant. If you run it you will damage it. The pump, lines, fittings etc need to be able to handle the high ethanol.
 

sc_rhino

Member
What are we talking E10, E85? I've run E10 before in a pinch and didn't notice any difference. I'm pretty sure E85 would be a bad idea

E10 is regular gas. Ethanol free gas is usually premium which a lot of people use for small engines that aren't used a lot.
 

JoeB-JKURX

New member
2014 JK Fuel

I checked the (massive) owners manual for my Jeep. It says "To fix a Non-FFV vehicle inadvertently fueled once with E-85 perform the following: • Drain the fuel tank (see your authorized dealer)." Damage caused by using high ethanol fuel is not covered by the warranty.

It is written on the web in quite a few places, however, that the Pentastar was originally designed to be a flex fuel engine.
 

JK_Dave

Caught the Bug
A new tune and new higher flow injectors that can support E85 would be required as well. To be honest, it's not really worth doing to your motor.

E85 has a much higher octane rating than premium gasoline. As such, you can run more advance and if you were boosted (turbo or s/c) you could turn up the boost to inject more air. E85 is also cheaper than gasoline.

Trade offs include the fact that E85 has less energy content than the same gallon of gasoline. That's why you get worse mpg on it because you're using more of it, all other things being equal with gasoline. Plus, it has more water in it and as others have said, your fuel tank and lines have to be able to support it.
 

highoctane

Caught the Bug
My '13 Grand Cherokee Trail Hawk with the 3.6 got just over 11mpg on E85, and E85 at the time was a few cents moe than 87 octane. I tried it for 2 tanks to see how it did. The only thing it did was make my wallet smaller. Not worth it at all.
 

JK_Bbargers

New member
Thank you folks for answering my question many times over! Doesn't sound like it's worth digging into but it's still really good to know next time I'm asked that question
 
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