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3.6 - For Those Running Premium Fuel

GtX

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Well these days most government agencies are reliable with information and studies.... wait, no.
Your right, you should run race fuel at 110 octane exclusively in you NA six cylinder. If 87 to 93 got you +3 MPG then 110 should be good for +12, right?
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HoundDude

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I can tell the difference between Shell 93 and other top tier premium gas (Sunoco, BP, Conoco,...) with same octane rating. Shell 93 is the only thing that completely eliminates low RPM pinging in my 3.6 during the hot/humid mid-atlantic summer months. in winter, I can get away with 87 or 89. I don't really pay attention to mpg so dunno about that.
 

Jeepileptic

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I can tell the difference between Shell 93 and other top tier premium gas (Sunoco, BP, Conoco,...) with same octane rating. Shell 93 is the only thing that completely eliminates low RPM pinging in my 3.6 during the hot/humid mid-atlantic summer months. in winter, I can get away with 87 or 89. I don't really pay attention to mpg so dunno about that.
+1 on this
 

GtX

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OP said nothing about knock on his claim of +3 from 93 octane. In fact, he said he had no knock on 87.

I count on your posts and how they rely on information related but not included to seem relevant. You did not disappoint this evening. Bravo.
 

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Bearded_Dragon

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Investigate and research the 3.6 a little more and it may surprise you that the higher compression engine thrives on higher octane fuel. Believe Livernoise just posted something about their tuner recently and also provided background info on how much better the 3.6 delivers all around with premium fuel. I can’t find the thread right now but I’ll post it if I can.
The JL tune is not the same as other 3.6L in cars. If you tune your JL 3.6L for 93 or ethanol fuel then yes it will make more power and maybe more MPG.
 

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Another factor to consider is that some high octane fuel not does have ethanol (i.e., pure gas). Non-ethanol gas has more BTU's (Power) than gas with ethanol. However, ethanol reduces the chances that knocking (pre-detonation) will occur.

At the end of the day, max HP and max MPG is a complicated equation that has many variables.
 
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breakerbaker

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Pretty awesome video from Chris. Explains in depth with some great animations. This should leave you all with no questions
 

Jebiruph

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For those running premium fuel, what are you seeing (MPG increase and overall improvements if any).

I’m seeing the 3.6 is 11.5:1 compression, and more and more forum discussions for other vehicles that run the Pentastar are using premium with good success.

weather and wind have been fairly consistent here in NE Ohio and over the last 6 days I ran through 2 tanks, seeing just over 3 MPG better on highway runs back and forth to the same place helping my father in law move his inventory from a Snap On truck.

was getting 17 to 17.5 MPG andover the last two tanks of premium have been seeing 20.7 to 21.1. Didn’t have any knock issues or anything before this so running performance (if you can call the Wrangler anything performance related) hasn’t changed much.

Just interested in other feedback.
Is it possible the premium was straight gas and the other gas 10% ethanol? On vacation last year I saw a 3 to 4 mpg variance between 87 octane straight gas and 10% ethanol.
 

rubileon

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For those running premium fuel, what are you seeing (MPG increase and overall improvements if any).

I’m seeing the 3.6 is 11.5:1 compression, and more and more forum discussions for other vehicles that run the Pentastar are using premium with good success.

weather and wind have been fairly consistent here in NE Ohio and over the last 6 days I ran through 2 tanks, seeing just over 3 MPG better on highway runs back and forth to the same place helping my father in law move his inventory from a Snap On truck.

was getting 17 to 17.5 MPG andover the last two tanks of premium have been seeing 20.7 to 21.1. Didn’t have any knock issues or anything before this so running performance (if you can call the Wrangler anything performance related) hasn’t changed much.

Just interested in other feedback.
I only run the best fuel we can get here which is RON98 which is said to be the US 93 equivalent. I get 16.8 MPG or a tad better in mixed use (3.6, auto, no eTorque).

During cold months it might not matter as much but during hot weather you can notice a difference in low rpms and under load, which is almost everytime you accelerate in traffic.

A tuner in the forum has said that the engines run cooler with higher octane fuel also.

All that aside, premium fuel is sometimes more than the octane rating. I want to delay EGR and the like clogging up as much as I can also.
 

ChrispyJL

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If you see a difference then use premium.
Don't post about it on a forum, because well, you see.
Someone can find an article from someone that says blah blah blah premium does nothing when it says you can use 87.
Maybe it is because it is july and all the planets are lined up.

I would believe my own eyes and brain, and not listen to naysayers that read an article once.
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