Hemi Ping

[06 Dodge]

What?! A major corn state doesn't force ethanol gas?!

Well they didn't as of last year ( aka 2022) when I was talking to one of my cousins about ethanol BS in gas

 

[HEMIMANN]

Well they didn't as of last year ( aka 2022) when I was talking to one of my cousins about ethanol BS in gas

Yeah I guess IA doesn't have Cargill like we MN do or ADM like IL does.

 

[pscarbor]

Post up this owner manual page specifying 93,take a picture and post it. I think you might want to get your eyes checked,as even the high compression 6.4's in the cars only call for 91

Why would I do that? I have no need to "prove" anything to you or anyone else.

 

[HEMIMANN]

Why would I do that? I have no need to "prove" anything to you or anyone else.

Because none of us have a Hemi calling for 93 octane, maybe?

Just a wild guess.

 

[Wild one]

Why would I do that? I have no need to "prove" anything to you or anyone else.

Is that because you were wrong and hate to admit it No "stock naturally aspirated " hemi calls for 93. In alot of areas 93 isn't even available,so they aren't going to build something you can't buy fuel for

 

[pscarbor]

Is that because you were wrong and hate to admit it No "stock naturally aspirated " hemi calls for 93. In alot of areas 93 isn't even available,so they aren't going to build something you can't buy fuel for

So essentially I suggested the OP check his owner's manual and see what octane Dodge recommends. If I am interpreting your post you are responding, "Naaah, don't bother with that."

Incorrect or too low octane can cause pre detonation or "knock", especially if you fill up in a high altitude area (lower octane) and then drive to a lower altitude. But I bet your owner's manual doesn't say that either.

For reference, here is what the 2009 Dodge Service Manual says:

Fuel Selection (5.7L) 95 RON, 89 Octane (R+M)/2 Method, Mid-Grade Preferred (91 RON acceptable)
RON is the "R" in the auto octane formula, or Research Octane Method. "M" is Motor Octane method and is usually a lower number. 95 RON is usually somewhere between 91 and 93 Octane.

I will repeat what I suggested to the OP, which is: Check your owner's manual, and follow its recommendations.

 

[Wild one]

So essentially I suggested the OP check his owner's manual and see what octane Dodge recommends. If I am interpreting your post you are responding, "Naaah, don't bother with that."

Incorrect or too low octane can cause pre detonation or "knock", especially if you fill up in a high altitude area (lower octane) and then drive to a lower altitude. But I bet your owner's manual doesn't say that either.

For reference, here is what the 2009 Dodge Service Manual says:

Fuel Selection (5.7L) 95 RON, 89 Octane (R+M)/2 Method, Mid-Grade Preferred (91 RON acceptable)
RON is the "R" in the auto octane formula, or Research Octane Method. "M" is Motor Octane method and is usually a lower number. 95 RON is usually somewhere between 91 and 93 Octane.

I will repeat what I suggested to the OP, which is: Check your owner's manual, and follow its recommendations.

Check your owners manual,and find us the page where it says 93 octane,post that page up. Hell there's lots of places you can't buy 93 octane fuel,and you think they're going to build a truck that you can't buy fuel for,give your head a shake man,and wise up.The manual says to use 89,but 87 is acceptable,that's what your 09 manual will also say.Even the higher compression SRT 6.4's only call for 91 octane.

 

[HEMIMANN]

R+M/2 octane rating - not Canada RON octane rating

 

[Wild one]

So essentially I suggested the OP check his owner's manual and see what octane Dodge recommends. If I am interpreting your post you are responding, "Naaah, don't bother with that."

Incorrect or too low octane can cause pre detonation or "knock", especially if you fill up in a high altitude area (lower octane) and then drive to a lower altitude. But I bet your owner's manual doesn't say that either.

For reference, here is what the 2009 Dodge Service Manual says:

Fuel Selection (5.7L) 95 RON, 89 Octane (R+M)/2 Method, Mid-Grade Preferred (91 RON acceptable)
RON is the "R" in the auto octane formula, or Research Octane Method. "M" is Motor Octane method and is usually a lower number. 95 RON is usually somewhere between 91 and 93 Octane.

I will repeat what I suggested to the OP, which is: Check your owner's manual, and follow its recommendations.

Seeing as how you haven't checked your owners manual ,you might want to read this page.This is from the 700 page printed manual for the trucks

 

[Wild one]

@Wild one

Contemplating some more, Mopar didn't differentiate fuel octane rating recommendations from the higher compression 5.7 to the lower compression 6.4 BGE engines in truck owner's manuals.

Do you think the compression ratio difference was too insignificant to drop the 89 to an 87 recommended in the 6.4?

In other words, you're saying running 89 in the 6.4 is less likely to have any pinging than with the 5.7?


Without datalogger data I'm becoming more inclined to run 91 Top Tier, because those corporate bozos won't answer technical questions about their damn products. I can afford it because I don't put that many miles on unlike some of you. I'm also thinking Top Tier gas certification, especially Shell (which overspikes additive beyond TT) would clean any deposits formed from incomplete combustion of 91 octane gasoline using 89 octane engine ignition timing?

Thoughts?

I finally got around to checking my 700 page printed manual,and it looks like they do differentiate between the 5.7 and 6.4,at least in this manual they do.

 

[HEMIMANN]

Not in my manual - the small one that comes with the truck.
For both 5.7 and 6.4 it says 89 preferred, 87 acceptable.

To the point above, yes 6.4 w/lower compression ratio has to be slightly less sensitive to knocking with same octane gas and ignition timing. But don't know if ignition timing maps are the same. If they are, then yes.

 

[Wild one]

So essentially I suggested the OP check his owner's manual and see what octane Dodge recommends. If I am interpreting your post you are responding, "Naaah, don't bother with that."

Incorrect or too low octane can cause pre detonation or "knock", especially if you fill up in a high altitude area (lower octane) and then drive to a lower altitude. But I bet your owner's manual doesn't say that either.

For reference, here is what the 2009 Dodge Service Manual says:

Fuel Selection (5.7L) 95 RON, 89 Octane (R+M)/2 Method, Mid-Grade Preferred (91 RON acceptable)
RON is the "R" in the auto octane formula, or Research Octane Method. "M" is Motor Octane method and is usually a lower number. 95 RON is usually somewhere between 91 and 93 Octane.

I will repeat what I suggested to the OP, which is: Check your owner's manual, and follow its recommendations.

Here i dug up a 2013 manual,it also says 87 acceptable,but 89 reconmended

 

[Wild one]

Not in my manual - the small one that comes with the truck.
For both 5.7 and 6.4 it says 89 preferred, 87 acceptable.

To the point above, yes 6.4 w/lower compression ratio has to be slightly less sensitive to knocking with same octane gas and ignition timing. But don't know if ignition timing maps are the same. If they are, then yes.

That's one thing i've never seen is the timing maps comparing the 2 engines. I know the 6.4 is supposed to be able to tow on pretty well warm p!$$,lol. But whether it's got a slower timing map i don't know.

 

[Wild one]

Check your owners manual: Doesn't it specify 93 octane gas? Mine does. I have two Dodge 5.7 hemis; both are on 93 and neither pings.

Still waiting for this picture showing where your owners manual specifies 93,you must have the "special" manual,as every other manual is like this one and says 89 reconmended but 87 is acceptable. BTW: 93 Ron is more akin to 89 octane in the US and Canada,are you sure you don't have the 2 mixed up