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What fuel for 5.7
- Thread starter Kapnbill
- Start date
J
jimh4662@
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I emailed technical support at Mopar back in 2014, they explained the engine and computer is programmed to run 89 octane as stated preferred in the ownership manual at least it was in 2014. They further explained the computer programmed best running scenerio was at 89. But the computer will adjust to fuel rated at 87. So in my 2014 I ran every tank with 89.
The way I figured, the truck was designed for 89 why cause the system a change or alter the norm and tolerate 87. If it didn't matter why didn't the specify USE WHAT EVER YOU WANT.
The way I figured, the truck was designed for 89 why cause the system a change or alter the norm and tolerate 87. If it didn't matter why didn't the specify USE WHAT EVER YOU WANT.
D
Deleted member 85
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I've found our trucks drive the same with any Octane. My Charger, however, f#*$&ing loves 94 octane.
2019REBEL
Spends too much time on here
I work at the airport let me get you some jet fuel at $5 a litreBobbiBigWheels said:
Twoamen
Well-Known Member
Manual states for best performance and economy 89 recommended. I ran ever tank on my 2014 with 89. So far every tank on 2019 is 89. The owners who feel 87 is fine I figure they sell 87 everywhere they sell 89. Seems to me theres significant reason to tune the 5.7 for 89. Or They wouldn't have recommended it.
D
Deleted member103
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AS DOES THE BANK HANDLING YOUR CREDIT/DEBIT CARD . . .
. . . Unless you use cash 9 ( like me ).Have a 2016 Sport Reg Cab with the 3.92 rear and it hauls butt on 87 octane without so much as a ping. Remember when you had to loosen your distributer and retard the timing? These engines today with computers can think and respond in a nano second to any input from light throttle to mashing the pedal. But if 89 gives you peace of mind than stick with it.
I've ran my 16 at the track with 87 and with 91. It didn't pick up so much as a tenth of a second with the 91 and doesn't ping or do anything weird with the 87 in it so I just stick to that. Gas is also the equivalent of $6+ a gallon here so that helps make my decision lol.
Twoamen
Well-Known Member
Don't have credit card. Lou2.... thats why I use 89. Here is another stone in your shoe for "the why pay more group" I use full synthetic oil in all my combustion engines. Is it Recommended? Hmm!
I only put 6-7K miles per year on my truck, so I put in 93 for fuel stability as much as for performance. Of course, I've also had my current truck tuned for the higher octane 
I only put 6-7K miles per year on my truck, so I put in 93 for fuel stability as much as for performance. Of course, I've also had my current truck tuned for the higher octane
I'm really thinking about doing a custom tune, but not looking forward to fuel prices.
YardSale
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Not that I know anything about fuel but.............if you can run regular without damaging the engine and there's no discernable performance/mileage benefit using higher octane ......why would you spend (i.e. throw away) the extra $$$?
You wouldn't. Or at least I wouldn't. But if 89 is recommended and you choose to run 87, you might notice the reduction in power (or even hear some knocking) under heavy load, indicating that you need to run a higher grade (presuming a well-tuned engine). I mentioned a couple of other reasons above for running a premium grade.
YardSale
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I get it Bro.......used to have a Challenger SRT and it only saw the high grade stuff! It just appeared to me that several folks here indicated they didn't have any problems even under load. I won't have my 1500 until end of July probably and will definitely be trying out the different grades just to see if I notice anything. In any case I suppose the question becomes does long term use of less than the recommended octane create issues?
Twoamen
Well-Known Member
Why is 89 recommended by the manual? Mopar getting kickbacks from oil companies I guess? . Most owners follow there manual to maintain warranty integrity. Anyhow I'm comfortable with following the recommended 89 octane. Ran it totally in the 2014 I traded on the 2019. I'm out!
On my current truck ('03 GMC 1500HD), I did a ride-along tune with Justin (Black Bear). The benefit was that he was tuning for my specific truck's idiosyncrasies and modifications (e.g. custom cat-back exhaust, upgraded spark plugs), as opposed to a generic tune. We removed most (not all!) of the 6.0L/4L85-E engine management and torque management protection, optimized it for a higher octane, and really "woke up" the truck. 7 years later, "Junior" is still running strong.
