Regular, Plus or Supreme Gas in the 6.4 Hemi

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Iron Outlaw

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Hemi 6.4
You guys made me spit gatorade on my phone.


I runderstand 87 unless I'm towing then I put 93. Don't really think it makes a difference.
 

fritotec

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cummins
I noticed that the last post on the thread was 18 months ago but it pretty much answered the question I had. I just wonder why my service advisor, the guys wrenching in the back would tell me it will throw a code and could damage the engine if I put regular or mid-grade in the tank.
 

smurfs_of_war

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^^ what he said. I run ****** 87 out of an old gravity fed farm tank and she chugs along happily getting decent mileage and never skips a beat towing.

Sent from my mobile
 

WaterBoy1

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Ontario
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2014 Laramie CC2500 Black Edition
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I've been running 91 lately, and not really for any other reason than my truck sits a lot of the time. It takes me around a month to go through a tank of gas. I figure less chance of the fuel going bad that way.

Works for my small engines (chainsaw/mower/trimmer/etc) so why not lol

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sandawilliams

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85 here. (Colorado) I've tried all grades and there was no difference in mileage or power either empty or towing. Have towed with this truck over 35000 miles now and was hoping if I upgraded to 89 I would notice a difference but after many tanks no deal.
 

GsRAM

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I've been running 89 since I bought the truck a year ago because the owners manual stated that was the preferred or recommended fuel in it.

after reading these posts I may give a few thanks of 87 a shot. especially this time of year when it's do cold out. 89 in my area is about 30 cents more per gallon so it adds up.
 

skHemi64

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I do 85 octane here in Colorado. It "seems" like mid-grade feels better towing. I have 10k+ towing from CO to FL and MD.
 

Deki

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I go with whatever the manual says. I'm not an engineer and they built the thing. 89 every time.
 

Black Gold Ram

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I noticed that the last post on the thread was 18 months ago but it pretty much answered the question I had. I just wonder why my service advisor, the guys wrenching in the back would tell me it will throw a code and could damage the engine if I put regular or mid-grade in the tank.

From the owners manual 20171101_111713.jpg
 

Don Padgett

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I only pull with my 2500. My rv is 10k. I save money by using stp to obtain obtain boost using 87 gas. WWay cheaper than 90 at pump. I make long trips for the most part. New Mexico to Montana at least once a year. All fairly high elevation driving. I definitely notice mileage dif based on octane. 8 mpg with straight 87 12 average with 90. A lot of up down on the highways and 90 shines heading up. Had diesel before. Never again for me. Take off night and day difference. Going around slower traffic while pulling the rv is awesome with the 6.4. 90 mph not a problem when passing with 90 octane.
 

j_t_l

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Hemi 6.4
I only pull with my 2500. My rv is 10k. I save money by using stp to obtain obtain boost using 87 gas. WWay cheaper than 90 at pump. I make long trips for the most part. New Mexico to Montana at least once a year. All fairly high elevation driving. I definitely notice mileage dif based on octane. 8 mpg with straight 87 12 average with 90. A lot of up down on the highways and 90 shines heading up. Had diesel before. Never again for me. Take off night and day difference. Going around slower traffic while pulling the rv is awesome with the 6.4. 90 mph not a problem when passing with 90 octane.

From the manual:
MMT In Gasoline
Methylcyclopentadienyl Manganese Tricarbonyl (MMT) is a manganese-containing metallic additive that is blended into some gasoline to increase octane. Gasoline blended with MMT provides no performance advantage beyond gasoline of the same octane number without MMT. Gasoline blended with MMT reduces spark plug life and reduces emissions system performance in some vehicles. The manufacturer recommends that gasoline without MMT be used in your vehicle.

STP octane booster uses MMT.

As they say, your mileage may vary...
 

j_t_l

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We must have different manuals.
From the 2019 Ram 2500/3500 owners manual:
This engines is designed to meet all emissions regulations and provide satisfactory fuel economy and performance when using high quality unleaded gasoline having a posted octane number range of 87 to 89 as specified by the (R+M)/2 method. The use of 89 octane “Plus” gasoline is recommended for optimum performance and fuel economy.
 

scott lass 18

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mine new ran like doo doo bang bang no power sucks then in back of my book says run 89 hummm it made mine run sooo great idle great but to low I feel now tuner 91 oct did a lot of upgrade runs so much better and snog test say it wasn't bad even better then trucks like me hummm this mds I feel may get us a 1 mpg but I turn off now like I said the valves are burning up on people here u can read it all ! even on police cars idle a lot 26 psi oil low idle 500 not 650 like others so guess set up to die early on people way to go dodge !
 
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