DODGE RAM FORUM - Ram Forums and Owners Club! - Dodge Truck Forum

Go Back   DODGE RAM FORUM - Ram Forums and Owners Club! - Dodge Truck Forum > Dodge Ram Forum - Help Zone - Dodge Ram Problems, Complaints, & Solutions - Maintenance & Re > Dodge Ram MPG Zone


Notices

Dodge Ram MPG Zone Discuss your MPG woes and helpful hints here!


Latest Vendor News
AutoAnything
Addictive Desert Designs!
United Radio
Bayou Goat Mounts

Reply
 
Thread Tools
  #1  
Old 06-06-2012, 06:41 PM
j6harris j6harris is offline
Dodge Ram Forum Newcomer
 
Join Date: Jun 2012
Location: mn
Age: 32
Posts: 11
Gender: Male
Vehicle: 2012 ram 1500
Trim Level: big horn
Color: black
Engine: 2009-20?? 345ci (5.7L) Hemi V8 390hp 407lb/ft
Rep Power: 0
Rep:10
j6harris is on a distinguished road
Default octane rating

does anyone know why the manual recommends to use 89 octane instead of 91 or 93 with a 10.5:1 compression ratio on the 5.7 hemi ?
Reply With Quote
Sponsored links
  #2  
Old 06-06-2012, 06:58 PM
pogster pogster is offline
Dodge Ram Forum Senior Member!
 
Join Date: Mar 2012
Location: AB
Posts: 487
Gender: Male
Vehicle: 2012
Rep Power: 0
Rep:13
pogster is on a distinguished road
Default

Because it's not needed. If you pulling a load for example it's better to use 89 than 87 to prevent pre-ignition or knock as its sometimes called. Using higher octanes would be a waste of money.
Reply With Quote
  #3  
Old 06-06-2012, 08:09 PM
PaulMys's Avatar
PaulMys PaulMys is offline
Misses the Champ.
 
Join Date: May 2012
Location: Long Island, New York
Age: 44
Posts: 5,839
Gender: Male
Vehicle: 2012 1500 reg. cab 4x4
Trim Level: Express
Color: Mineral Gray Metallic
Engine: 2009-2012 345ci (5.7L) Hemi V8 390hp 407lb/ft
Rep Power: 11
Rep:3248
PaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond repute
Default

I asked my dealer this same question when ordering my express back in March. He said that the new engines have been engineered this way, and as pogster stated, higher octane has no advantage or disadvantage so just a waste of money.
__________________
Pit Bulls are people too.
Reply With Quote
  #4  
Old 06-06-2012, 08:37 PM
docgatling docgatling is offline
Dodge Ram Forum Newcomer
 
Join Date: May 2012
Location: So Cal
Posts: 20
Gender: Male
Vehicle: 2012 Ram 1500
Trim Level: Outdoorsman 4X4
Color: white
Engine: 2009-20?? 345ci (5.7L) Hemi V8 390hp 407lb/ft
Rep Power: 0
Rep:10
docgatling is on a distinguished road
Default

In the old days if your motor suffered knock you switched to higher octane. Modern cars (and trucks!) have knock sensors to prevent damage to the engine if to low octane in injected. Your eingine will run but suffer in the preformance department. So, I would run a couple tanks of both and see how your engine performs. Monitor your gas mileage with 89 then try 91. If you don't see any difference use the "cheaper" stuff. There is a good article in Road and Track about octane and its effect on engines. It's not just about compression anymore.
Reply With Quote
  #5  
Old 06-06-2012, 08:53 PM
snrusnak's Avatar
snrusnak snrusnak is offline
Dodge Ram Forum Senior Member!
 
Join Date: Jan 2011
Location: Orlando
Age: 27
Posts: 13,386
Gender: Male
Vehicle: 2010 Dodge Ram 1500
Trim Level: SLT
Color: White
Engine: 2008-20?? 287ci (4.7L) PowerTech V8 310hp 330lb/ft
Rep Power: 12
Rep:1385
snrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud of
Default

The two biggest factors that relate to required octane are compression and ignition timing advance. From the factory with stock tune, 89 octane is recommended. It will run on 87 but may retard timing slightly(slightly less performance/mpg).
__________________
Sean

Breathing in and out is good enough for me.
Reply With Quote
  #6  
Old 06-06-2012, 08:57 PM
GTyankee's Avatar
GTyankee GTyankee is offline
Dodge Ram Forum Member

 
Join Date: Dec 2009
Location: San Diego East County, Ca
Posts: 19,026
Gender: Male
Vehicle: 2009 Dodge Ram 1500 2X4
Trim Level: quad cab SLT
Color: sunburst orange pearl
Rep Power: 20
Rep:2615
GTyankee has a reputation beyond reputeGTyankee has a reputation beyond reputeGTyankee has a reputation beyond reputeGTyankee has a reputation beyond reputeGTyankee has a reputation beyond reputeGTyankee has a reputation beyond reputeGTyankee has a reputation beyond reputeGTyankee has a reputation beyond reputeGTyankee has a reputation beyond reputeGTyankee has a reputation beyond reputeGTyankee has a reputation beyond repute
Default

I have run my HEMI on 87 octane, when the prices were too high
I usually run 89, better gas mileage & more responsive

I wouldn't run the octanes that are higher yet, unless i had something like this

__________________
Ram 1500 SLT Quad cab, 5.7 HEMI(R) MDS VCT, 5 speed auto 545RFE, 3.55 differential gears, 18" Magnaflow muffler, EGR bug deflector, Bushwacker fender flares, customized Nfab nerf bars, CB radio, Autonet wi-fi router, custom soft tonneau cover, Line_X bedliner, DEBO Step, build date 10/15/08 a Wednesday built vehicle
Reply With Quote
  #7  
Old 06-06-2012, 09:00 PM
PaulMys's Avatar
PaulMys PaulMys is offline
Misses the Champ.
 
Join Date: May 2012
Location: Long Island, New York
Age: 44
Posts: 5,839
Gender: Male
Vehicle: 2012 1500 reg. cab 4x4
Trim Level: Express
Color: Mineral Gray Metallic
Engine: 2009-2012 345ci (5.7L) Hemi V8 390hp 407lb/ft
Rep Power: 11
Rep:3248
PaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond reputePaulMys has a reputation beyond repute
Default

GT- now THAT'S a HEMI!
__________________
Pit Bulls are people too.
Reply With Quote
  #8  
Old 06-09-2012, 02:30 AM
captainchubbzz captainchubbzz is offline
Dodge Ram Forum Senior Member!
 
Join Date: Feb 2012
Location: United States
Posts: 124
Gender: Male
Vehicle: 2012 Ram 1500 5.7L Hemi
Trim Level: Express
Color: Mineral Gray Metallic
Engine: 2009-20?? 345ci (5.7L) Hemi V8 390hp 407lb/ft
Rep Power: 0
Rep:10
captainchubbzz is on a distinguished road
Default

I've used an 88 octane with no ethanol, it truly made a difference in power and my engine seemed much happier. I could be up in the night though?
Reply With Quote
  #9  
Old 06-13-2012, 12:11 PM
j6harris j6harris is offline
Dodge Ram Forum Newcomer
 
Join Date: Jun 2012
Location: mn
Age: 32
Posts: 11
Gender: Male
Vehicle: 2012 ram 1500
Trim Level: big horn
Color: black
Engine: 2009-20?? 345ci (5.7L) Hemi V8 390hp 407lb/ft
Rep Power: 0
Rep:10
j6harris is on a distinguished road
Default

well heres what i came up with .
i tried 3 different types of gas, all 3 were from bp .
89 , 93, and non oxygenated 91

89- the gas mileage is ok, the throttle response is best at low to medium speeds/rpm no load just normal putzing around neighborhood kinda driving or freeway on ramp type area ... anywhere you'd keep the pedal at 3/4 or less it shines , 89 is what the factory recommends but it lacks the full throttle go and mileage of 91 or 93.

non oygenated 91- it lasted forever.. almost 2 weeks on what a tank of 93 oxygenated going the same places would last me in 1 week.. the only problem with that was i couldnt wait to get it out of my tank. there was almost no throttle response. seemed like i could only go all or nothing, it was fine idiling around at low speeds/rpm except when it came to normal driving conditions like accelerating from stop lights and freeway entrances it was very sluggish like i was using syrup for gas but when i opened it up it went like a raped ape! .. that part was nice but i do a good amount of normal driving so this one wasnt for me. plus i hear its more corrosive than oxygenated gas.

93- 93 is what i've been using for a few years now on the 5.7 hemi. the down sides are its more expensive and the low end throttle response isnt as good as with 89 but that is just barely noticable. the gas mileage is a noticable amount better, lasted me 2 days longer than 89 did going to the same places. when you put the pedal to the medal with 93 it goes! i've never felt a vehicle accelerate like this one, it seems like the power curve doesnt curve it just rises.. its nice, fun to drive and i like how it pushes you harder into the seat the longer you've been on the gas.

so.. i decided i'm sticking with my 93 because it suits my driving habits better, i like to open it up from time to time and i have bragging rights to uphold at work when all my chevy and ford loving buddies want to eat some dust i'll be there to serve it to them with that extra ooomph i get from 93, but all around i guess the octane rating really depends on how and where you drive, personally if you do a lot of towing or hauling or friendly races to make your buddies cry i would recommend using a higher octane because it really makes a difference in power when you add more throttle but i'm no expert..
i have a buddy at work that also has a 2012 ram thats been using 87, he doesnt mind it but i dont think he cares or pays attention to the little details in things like i do, after i talked to him about octane he did put a tank of 89 in though haha, i'll have to see if its noticeably different or not especially when he's towing his boat
... my only question now is what will the different octanes do to an engine over time, it would be nice to know how much carbon buildup/ deposits changes between octanes and if certain engine wear patterns or damage occurs between octanes....
Reply With Quote
  #10  
Old 06-13-2012, 12:21 PM
snrusnak's Avatar
snrusnak snrusnak is offline
Dodge Ram Forum Senior Member!
 
Join Date: Jan 2011
Location: Orlando
Age: 27
Posts: 13,386
Gender: Male
Vehicle: 2010 Dodge Ram 1500
Trim Level: SLT
Color: White
Engine: 2008-20?? 287ci (4.7L) PowerTech V8 310hp 330lb/ft
Rep Power: 12
Rep:1385
snrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud of
Default

Wow man. Most of the changes that you noticed between those fuels is in your head. Using 93 octane instead of 89 octane on the hemi will not give you any more power or mpg(at any rpm). It will help promote carbon buildup, though. This is assuming it's running the stock tune.

It's been discussed a million times, and there are reasons behind it. The hemi will run on 87 no problem. It will produce slightly more power and mpg on 89. Slightly does mean slightly; switching from 87 to 89 won't give you 50hp so you can beat your buddy's chevy. The difference likely isn't even noticeable to the driver(maybe 5hp?). Anything more than 89 is just throwing money away and promoting carbon buildup, so you'd actually be doing better for the engine and your wallet to put 89 in instead of 93.

Now I will say that I have no idea what oxygenated or non oxygenated fuel is...so I won't comment on that other than I guarantee you didn't doubled your mpg with it...
__________________
Sean

Breathing in and out is good enough for me.
Reply With Quote
Reply

Bookmarks

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


Advertisement






All times are GMT -4. The time now is 07:42 AM.


= Copyright RamForumZ.com a Gigathreads.com Network Site =Ad Management by RedTyger
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
vB.Sponsors


=Gigathreads Network=
CLUBS MOPAR NATION DSM GPMM MAMM JAM
DIESEL Diesel Forum      
CHEVY Chevy Camaro Forum Chevy Volt Forum    
CHRYSLER Chrysler 300C Forum      
DODGE Dodge Avenger Forum Dodge Caliber Forum Dodge Challenger Forum Dodge Charger Forum
  Dodge Circuit Forum Dodge Hornet Forum Dodge Magnum Forum Dodge Nitro Forum
  Dodge Ram Forum Dodge Dakota Forum Dodge Durango Forum Dodge Dart Forum
FORD Ford Raptor Forum Ford F150 Forum Ford F100 Forum  
JEEP Jeep Forum      
PONTIAC Pontiac G8 Forum      
SRT SRT Viper Forum SRT Cuda Forum