Reading the owners manual, it says 89 gasoline is recommended as it using Top Tier gasoline. The only Top Tier gasoline available locally does not hav

[Scram1500]

Such blatant use of the r-word. I believe the current nomenclature is "intellectual disability". Not sure what we are supposed to do with the master and slave cylinder faux pas

 

[SnowBlaZR2]

..........which is exactly why they said multiple times that you should use the lowest octane you can without detonation. And the Ram doesn't detonate at 87 octane because the tune is designed for it per the Ram owners manual.

So basically you just told us nothing.

It's fascinating to me that you think the manual recommends 89 for the hell of it.

 

[HSKR R/T]

..........which is exactly why they said multiple times that you should use the lowest octane you can without detonation. And the Ram doesn't detonate at 87 octane because the tune is designed for it per the Ram owners manual.

So basically you just told us nothing.

And how do you know there is no detonation in your cylinders on 87? Are you monitoring stknk and ltknk with a scan tool?

 

[Idahoktm]

One video on YouTube isn't the end all be all for how it works. If there was no need for different octane levels, the oil companies wouldn't make different octane levels. And tuners wouldn't require certain octane levels based on the tune. If you understand how octane works, then that video is what doesn't make sense

Edit: watched video again, even though I had in the past, just to refresh my memory. They explain in the beginning why none of them would run 87 in that engine in the street. Octane is just a resistance to detonation. The power potential of the fuel doesn't change.

I never said there was no need for higher octane fuels.

So while you CAN run 87, it MIGHT reduce the performance of the engine IF the PCM pulls timing.

I agree with your statement above with two minor word changes, because you can't definitively say that it "will reduce performance or pull timing". As far as the Hemi goes, 89 octane fuel may be required under certain conditions in order to produce optimum hp/torque. That said, you should run the fuel that you are comfortable running and I really don't care either way...I run 89 myself. I only made the earlier comment because 87 won't always have a negative effect on performance.

 

[SnowBlaZR2]

 

[theblet]

 

[HSKR R/T]

I never said there was no need for higher octane fuels.


I agree with your statement above with two minor word changes, because you can't definitively say that it "will reduce performance or pull timing". As far as the Hemi goes, 89 octane fuel may be required under certain conditions in order to produce optimum hp/torque. That said, you should run the fuel that you are comfortable running and I really don't care either way...I run 89 myself. I only made the earlier comment because 87 won't always have a negative effect on performance.

My initial sentence was more accurate. Was no need for any changes. I have monitored knock retard in previous Hemi powered vehicles and know the effect lower octane gas in it

 

[ferraiolo1]

Yep. On a modern engine, unless you’re monitoring it real time with a scan tool you generally will never notice whats going on.

Not like a ole sbc where you could rotate your distributer and tell when it was running better or worse with its fuel and timing.


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[FLiPMaRC]

No 88 octane is 15% which you can use. Usually the blue handle.

E85 in a perfect world should be 85%


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Filled up with 88octane at Sheetz last weekend while I was up in the Poconos. Did a bit of driving so I filled up twice. It was $4.55/gal. When I got back home to NJ, I noticed my dash is telling me 22mpg average. I usually fill up with 87 at Costco.

 

[Idahoktm]

My initial sentence was more accurate. Was no need for any changes. I have monitored knock retard in previous Hemi powered vehicles and know the effect lower octane gas in it

Absolutes rarely apply to anything, especially engine performance. Too many variables.

 

[theblet]

Absolutes rarely apply to anything, especially engine performance. Too many variables.

Moral of the story, you can run 87 if you want, as long as your truck runs fine on it. You will have less than max power. Run 89 if you need max performance. 89 didn’t make a fuel economy difference for me.

 

[Dewey]

Moral of the story, you can run 87 if you want, as long as your truck runs fine on it. You will have less than max power. Run 89 if you need max performance. 89 didn’t make a fuel economy difference for me.

You need 3.92’s to unlock the secret economy program.

 

[HSKR R/T]

Absolutes rarely apply to anything, especially engine performance. Too many variables.

It directly applies to this topic as knock is what the PCM uses to adjust timing in order for your engine to be able to safely run on 87. If there were too many variables to have it apply to anything there would be no need for knock detectors

 

[FLiPMaRC]

Filled up with 88octane at Sheetz last weekend while I was up in the Poconos. Did a bit of driving so I filled up twice. It was $4.55/gal. When I got back home to NJ, I noticed my dash is telling me 22mpg average. I usually fill up with 87 at Costco.

Filled up with E15 88oct again today before driving back home. After an hour drive ....

 

[bigdodge]

22.4 average
29 current at picture on 89 octane

 

[User_3336]

You need 3.92’s to unlock the secret economy program.

93 octane and 3.92's. optimum performance! LOL

 

[User_3336]

22.4 average
29 current at picture on 89 octane

View attachment 131395

Displaying a "CURRENT" mpg is kinda useless(its just the mpg you were getting "at the moment" you shot that pic.....you could have been going down a hill), as that is NOT the "average". 22.4 is good. I went on a 100 mile trip with several steep hills last week, and I got 21.9.

 

[bigdodge]

Displaying a "CURRENT" mpg is kinda useless(its just the mpg you were getting "at the moment" you shot that pic.....you could have been going down a hill), as that is NOT the "average". 22.4 is good. I went on a 100 mile trip with several steep hills last week, and I got 21.9.

party pooper


was flat ground

 

[User_3336]

part pooper

I did say 22.4 "average" was good! I could post my 50mph "current". I guess I could call that "instant" gratification!

 

[FLiPMaRC]

Displaying a "CURRENT" mpg is kinda useless(its just the mpg you were getting "at the moment" you shot that pic.....you could have been going down a hill), as that is NOT the "average". 22.4 is good. I went on a 100 mile trip with several steep hills last week, and I got 21.9.

3 miles of downhill