Question about 3.6L v6

[Sjung5]

Hi I just picked up 3.6l v6 rubicon
And would it be fine if I just put in regular gas over the premium?
Manual does state premium does not have any benefits over 87. Just wanted to see you guys opinion

also, are gasoline detergent beneficial forthis engine?

thanks! Very glad wrangler’s community is HUGE

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[Red Willy]

The 3.6 would likely run on kerosene I believe. I've always run regular in every Jeep I've owned (5 V6 and 1 inline 6) with no issues. I have started running premium lately as the Jeep sometimes sits for a few days at a time and doesn't get a lot of miles on it.

 

[Xcoaste]

87 is completely fine. I have never put anything else in a Jeep in over 20+ years.
I do use Top Tier fuel whenever I can.

 

[Miloe]

Coming up on 3 years of regular in a non-etorque 3.6, no issues so far.
Gets around 17 mpg in mixed driving.

 

[MaineBumpkin]

Always run 87 in ours and I use Red Line fuel system cleaner every 6 months.

 

[roaniecowpony]

I run Costco 87 in mine. No issues. But this engine has 11.3:1 compression. So the ability of running on 87 is pretty impressive.

 

[OBD]

I run 89 and get about 16.5 MPG short distance.But have less than 700 miles on the clock.

 

[Irish Creig]

I've had my 2021 JLU for 14 months and all I use is regular gas with no problems. In fact I've never used premium gas in any of my vehicles and they've all lasted beyond 13-14 years.

 

[jeepster345]

I run 89 and do more short distance driving. Probably nonsense, but I do feel a slight difference in running 89 vs. 87. Likely a placebo.

 

[Strommen95]

These threads tend to get juicy.

My 3.6 has felt fine on 87 and I've never experienced knocking. In fairness, I've never tried premium to feel if there's a difference, but with gas prices the way they are I aint gonna try it.

 

[tk1700]

I have a 2019 3.6 non torque and use 85/86 and no problems. Being at a higher altitude we don't have 87 available. I usually fill up at Sams club to avoid the long lines at COSTCO.

 

[blnewt]

We used to have 87 as our min octane fuel here, it's gone down to 86 for the last 2 years, no problems running that w/ our V6, and yeah, at least it's Top Tier.

 

[zrickety]

Hi I just picked up 3.6l v6 rubicon
And would it be fine if I just put in regular gas over the premium?
Manual does state premium does not have any benefits over 87. Just wanted to see you guys opinion

also, are gasoline detergent beneficial forthis engine?

thanks! Very glad wrangler’s community is HUGE

I go back and forth depending on the fuel prices. It does run better on premium, and the mileage is a little better. So I would argue there is a benefit. But 87 also seems to be ok.

 

[jeepoch]

Hi I just picked up 3.6l v6 rubicon
And would it be fine if I just put in regular gas over the premium?
Manual does state premium does not have any benefits over 87. Just wanted to see you guys opinion

also, are gasoline detergent beneficial forthis engine?

thanks! Very glad wrangler’s community is HUGE

Sung,

This topic comes up so very often with so many differing opinions. But more often than not most people 'believe' that the lower octane fuel is 'better' or at least 'good enough'. However in practice the lower octane fuel is generally not, especially in regards to engine knock.

Knock is a condition where the combustion event is not optimal with respect to any given engine load. With any suboptimal detonation event within any piston, some fraction of the power produced will actually work against (and retard) the crankshaft's rotation. Thus lowering the Engine's overall torque output. Worse, any unintended energy working against forward rotation causes mechanical disturbances that produce vibrations (knock) which detrimentally hurts the piston's rings and wall surfaces. This over time may lead to a loss of compression resulting in lower power, increased emmisions, more oil consumption and noticeably lower fuel efficiency.

Modern engines are designed to monitor and reduce engine knock rather well. The engine control computers 'react' to knock very quickly and may not even be noticeable by the driver. But rest assured with any knock event (whatsoever), regardless of reason is certainly lowering the overall lifetime reliability of your engine.

The lower the octane rating, the higher the probability of producing knock

Please reference a pretty detailed post I submitted on a similar thread describing this issue more deeply:

https://www.jlwranglerforums.com/forum/threads/do-we-have-to-run-premium.60627/page-2#post-1298593

I give reasons why you may want to consider running a higher than recommended octane fuel.

Regardless, I really believe that you will enjoy your 3.6L JL independent of whether you use the recommended fuel or better. Antiknock technology is petty good at readjusting Spark timing and delivered Fuel Injection pulsewidth to give a very good perception of good clean combustion. But as with most everything in nature, preventing problems before they happen (suboptimal combustion) rather than reacting and doing something after-the-fact (knock detection) is always the 'best' approach.

Regards,
Jay

 

[dsgrey]

No issue with 87 octane in mine. I've owned over two dozen vehicles and the only one that required a higher octane was a high compression 4 banger during summer temps. Granted there are vehicles that specifically state to run premium only.

One exception was a Datsun from the 70's with under 100hp that would run better on premium leaded back in the day.

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