3.6 engine and 87 octane a no-no

[jeepdabest]

I'm now using aircraft fuel and the idle has really smoothed out.

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[Petey]

I also think the tune is bit aggressive. As far as oil consumption, I've been using the oil life monitor (past two changes) and notice zero consumption on the dipstick. I drain about 2-3 oz out of the catch can every 2k miles so.. there's def oil being pushed though the PCV system but you won't notice that amount on the dipstick between 7500 mile oil
Does the vacuum source line have some traces of oil in it.. ? And which brand of catch can do u use?

 

[Deleted member 53226]

I'm now using aircraft fuel and the idle has really smoothed out.

LOL

Insurance Agent: So, what happened to the Jeep

Customer: Spontaneous fire. Damn'dest thing!

Insurance Agent: Uh, okay I guess. These things happen. Good news is you are fully covered. Bad news is our records on your Jeep make and model are not coming up in our system due to a glitch. So, what kind of Jeep was it and we'll send a check.

Customer: Ok, no problem. It was a 2020 Wrangler Unlimited Rubicon. Had every option!

 

[Petey]

I'm now using aircraft fuel and the idle has really smoothed out.

this is what my jeerp feels like at every long stop light

 

[Rodeoflyer]

Yes, the PCV line has oil in it and I went with a mishmoto can because it has a pet valve release under the driver side fender. Empties in seconds rather than having to open the hood and unscrew the can to empty.

https://www.mishimoto.com/jeep-wran...6oIYJym7qN3rpyzehvNW_LqqfkYQJhvRoCwp0QAvD_BwE

 

[DanW]

Straight from an FCA engineer who designed the Pentastar: It is designed to run perfectly on 87 octane. However, running premium fuel gains about 3 hoursepower (that's it) and it runs very slightly smoother, which most people won't notice.

Run what makes you feel good. But 87 is just fine. I've run 93 V-Power in mine and I didn't feel any benefit. So mine gets a steady diet of Top Tier 87 gasoline. Mostly Shell, but others, too, if I can't find it.

 

[mgroeger]

Straight from an FCA engineer who designed the Pentastar: It is designed to run perfectly on 87 octane. However, running premium fuel gains about 3 hoursepower (that's it) and it runs very slightly smoother, which most people won't notice.

Run what makes you feel good. But 87 is just fine. I've run 93 V-Power in mine and I didn't feel any benefit. So mine gets a steady diet of Top Tier 87 gasoline. Mostly Shell, but others, too, if I can't find it.

Hmmm... so does running 85 octane lose 3 HP?
Here in the St. George UT area 85 is the norm sadly and my manual Jeep does ping a little from it. I try to hit Costco where they carry 87 and it's .20/gal cheaper when I can. I'm cheap and right now gas is over $3 for 85 so I'll live with the ping... lol.

 

[Tread4Lo]

If this has to do with elevation, I'm at 500 feet (Northeast Texas). If I run 87 (Top Tier or grocery store brand), I have pinging while running around town. Most of my driving is this. Highways it would do fine while cruising, but any sort of additional throttle input would cause the rattle.

Switch over to 93 for the last 3-4 thousand miles. None of the above issues.

I know the manual says 87, it's clear as day. BUT with individual experiences and anecdotes, we all can't be full of it.

It's cost more and I wish I could run the 87 and not have the noise, but that isn't the case. I'll run the octane to make my Jeep not sound like a beater.

 

[timn1984]

I would be getting bad gas for the last 5k miles in that case ? I tell u its either lucas or high octane for from now on ... rather use lucas though

Well I might as well chime in, reluctantly, I might add. I use Premium or high octane or whatever you want to call the more expensive gas because my 2018 Sahara 3.6L pentastar runs better and smoother. There I said it!!!! Sit back and watch the fireworks......

 

[mgroeger]

If this has to do with elevation, I'm at 500 feet (Northeast Texas). If I run 87 (Top Tier or grocery store brand), I have pinging while running around town. Most of my driving is this. Highways it would do fine while cruising, but any sort of additional throttle input would cause the rattle.

Switch over to 93 for the last 3-4 thousand miles. None of the above issues.

I know the manual says 87, it's clear as day. BUT with individual experiences and anecdotes, we all can't be full of it.

It's cost more and I wish I could run the 87 and not have the noise, but that isn't the case. I'll run the octane to make my Jeep not sound like a beater.

I live in Hurricane UT which is 3300 above sea level so the standard is 85 here which sucks because it does cause the engine to ping. When I lived in NC, 87 was just fine at 300 feet above sea level. The article below also talks about this so for me I need to jump to 87 to get rid of the ping.

------------
They say the air is rare here in the Rocky Mountains, and that actually has an effect on how your engine performs. Because the air is less dense, less air flows to your car's engine. This translates to a slightly richer air-fuel ratio, and deters engine knock. For that reason, you'll find that regular gas carries an 85 octane rating here in Denver and throughout Colorado, Wyoming, Utah and Montana. In most states, regular unleaded is rated slightly higher at 87.

In most cases, you won't experience any problems running 85 octane in an ordinary car when a few thousand feet above sea level. However, if you do detect that tell-tale pinging noise, it may be wise to try filling your car with mid-grade gasoline which is rated at 87 octane here in Denver.

 

[Laststand]

Hmmm... so does running 85 octane lose 3 HP?
Here in the St. George UT area 85 is the norm sadly and my manual Jeep does ping a little from it. I try to hit Costco where they carry 87 and it's .20/gal cheaper when I can. I'm cheap and right now gas is over $3 for 85 so I'll live with the ping... lol.

Probably loses a lot more with 85 octane. I haven't seen an actual dynamometer test on the 3.6, but did have one posted when I had a 2004 Acura MDX.

Recommended fuel for the MDX is premium 91 octane or better. Using 93 octane the full rated HP was produced (265 for 2004), when he used 89 octane there was a drop of 7 HP (258) which was hardly noticeable unless towing or heavy loads. Dropping to 87 octane resulted in a further loose of 37 HP (221 HP) and very noticeable. ECM was very good at adjusting the engine (if memory serves me little or no pinging with the 87).

I currently have a RDX along with my JL and run 89 in the RDX no problem and 87 in the JL. However I do live at sea level, so that helps.

 

[dsgrey]

If this has to do with elevation, I'm at 500 feet (Northeast Texas). If I run 87 (Top Tier or grocery store brand), I have pinging while running around town. Most of my driving is this. Highways it would do fine while cruising, but any sort of additional throttle input would cause the rattle.

Switch over to 93 for the last 3-4 thousand miles. None of the above issues.

I know the manual says 87, it's clear as day. BUT with individual experiences and anecdotes, we all can't be full of it.

It's cost more and I wish I could run the 87 and not have the noise, but that isn't the case. I'll run the octane to make my Jeep not sound like a beater.

Interesting. Elevation plays a factor but I'm in north Texas at 545 feet. I only run 87 and haven't heard any pinging. The only time I've experienced pinging was in a high compression engine (Miata) and that was only during the summer.

 

[Petey]

Well I might as well chime in, reluctantly, I might add. I use Premium or high octane or whatever you want to call the more expensive gas because my 2018 Sahara 3.6L pentastar runs better and smoother. There I said it!!!! Sit back and watch the fireworks......

Amen brother ..preach it .. its not just a small difference either. My ass runs 87 octane the 3.6 pent. starts groaning with anything lower then 89-90

 

[Petey]

Hmmm... so does running 85 octane lose 3 HP?
Here in the St. George UT area 85 is the norm sadly and my manual Jeep does ping a little from it. I try to hit Costco where they carry 87 and it's .20/gal cheaper when I can. I'm cheap and right now gas is over $3 for 85 so I'll live with the ping... lol.

if i ran 85 in mine , rattle snakes would sue me for cultural appropriation.

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