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Has anyone run regular octane gas in their 392?

Left Field

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Heading out on an extended trip to the boondocks with the 392 in a couple weeks and in one area there is no premium gasoline available. Near as I can tell the 392 does not have a detonation sensor and hence does not adjust the ignition mapping based on octane (please correct me if that is wrong).
Some options that come to mind are:

1) Run regular gas & keep my foot out of the throttle.

2) Bring extra fuel, probably 10-15g required.

3) Octane booster
Not very excited about this. Most seem like snake oil, providing no quantifiable octane numbers. The legit ones such as Torco and Boostane appear to use MMT (Methylcyclopentadienyl Manganese Tricarbonyl) which is "not for highway use" and by at least some reports can damage O2 sensors and the cats.

My order of preference would be 1,2,3 but if someone has some experience I'd like to learn from it.
Thanks,
LF
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GATORB8

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Just a thought that may be worth looking into. IIRC, blending octanes results in a modified octane per the ratio.

What about bringing a smaller amount of something high octane (race gas) to raise the octane.
 

jludave

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Best bet is option 2 if you can swing it.
 

Old Dogger

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What part of our Country, doesn’t carry premium fuel? I didn’t know that this existed.
 
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Left Field

Left Field

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What about bringing a smaller amount of something high octane (race gas) to raise the octane.
Best bet is option 2 if you can swing it.
I think I'll do exactly this combination - bring fuel - but make it race fuel. Allows me to carry less fuel and still satisfy the octane requirements - Thanks!
LF
 

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Left Field

Left Field

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What part of our Country, doesn’t carry premium fuel? I didn’t know that this existed.
Burgdorf Idaho.

I can drive off-route some distance to get premium, but traveling with a group makes that side trip a logistical problem.
 

6.2Blazer

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I would pretty much guarantee that this engine has knock sensors and the ECM will retard the timing to compensate for lower octane fuel. Would be amazed if it didn't. Out of curiosity, what makes you think it does not have that capability?
And just before somebody jumps my case, I'm not saying the engine will run perfectly fine and have the same power if you run lower octane gas. But I would expect it to be able to run decent at reasonable throttle inputs and loads.
 

Quadjeeper

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I would pretty much guarantee that this engine has knock sensors and the ECM will retard the timing to compensate for lower octane fuel. Would be amazed if it didn't. Out of curiosity, what makes you think it does not have that capability?
And just before somebody jumps my case, I'm not saying the engine will run perfectly fine and have the same power if you run lower octane gas. But I would expect it to be able to run decent at reasonable throttle inputs and loads.
It does not retard timing. According to an engineer who developed the JL 392 package, it will damage the engine if less than 91 is used.
 

stumblinhorse

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It does not retard timing. According to an engineer who developed the JL 392 package, it will damage the engine if less than 91 is used.
Hmm…. Hold on there. You are saying that this sensor doesn’t do anything…. Just detects knock, and nothing happens….

https://www.oem-mopar.com/oem-parts/mopar-knock-sensor-5033316ab?c=Zz1lbGVjdHJpY2FsJnM9c2Vuc29ycyZsPTQmbj1TZWFyY2ggUmVzdWx0cyZhPWplZXAmbz13cmFuZ2xlciZ5PTIwMjEmdD11bmxpbWl0ZWQtcnViaWNvbi0zOTImZT02LTRsLXY4LWdhcw==
 
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Left Field

Left Field

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Hmm…. Hold on there. You are saying that this sensor doesn’t do anything…. Just detects knock, and nothing happens….
Some vehicles I've had say "Premium fuel recommended; lower octane fuel may reduce engine performance". This sounds like changing the ignition mapping if it detects detonation.

The 392 manual says "Use of gasoline with an octane number lower than recommended octane can cause engine failure and may void the New Vehicle Limited Warranty." ... "The use of 91 or higher octane “Premium” gasoline is required in these engines."

It would be pathetic, but perhaps the knock sensor just throws a 'bad fuel' code? Which unfortunately would then put your engine warranty in jeopardy...

LF
 

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Quadjeeper

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I'm not the engineer. Nor did I write the owners manual. Do what you want, but I'm not going to risk it.
 

JJMalone

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Detonation is not prevented by retarding ignition timing. Get a clue.
 

guarnibl

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Well that’s surprising given dealers around here just put 87 in the first full tank 392’s included.

I’d probably carry extra fuel though if I was OP. 2x or 3x cans and split them among guests if they’re cool with it and you don’t have the space.
 

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No.

The piece of mind when I put the skinny down is worth the extra $20 at fill-up.
 

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Make sure if you mix the race gas in that it is unleaded. Some high octane race fuel uses lead to boost octane numbers. Just a tip.
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