Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Grand Cherokee - WK2 - > Suspension/Driveline/Brakes/Wheels/Tires

Join Jeep Garage Today
Reply
 
Thread Tools Display Modes
 
  #1  
Old 05-10-2012, 08:07 AM
gaidin43's Avatar
Member
My Jeep: 2014 5.7L WK2
 
Join Date: Apr 2012
Posts: 216
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 1554
gaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond repute
89 octane for 5.7 Hemi recommended?

I was reading the manual and I noticed 89 octane is recommended for the 5.7 Hemi but 87 octane is acceptable.

What are people's thoughts on this? I've always used 87 octane in all my vehicles. I'm not sure how much of a performance increase or mpg increase I'd get for the increase cost of price per gallon.
__________________

__________________

2014 Jeep Grand Cherokee Limited | Max Steel | 4x4 | HEMI | Tow | ORA I | 8.4RA4
Previous Jeeps: 2012 GC Laredo X 5.7L
Reply With Quote
  #2  
Old 05-10-2012, 08:15 AM
Premium Member
My Jeep: 2012 5.7L WK2
 
Join Date: Nov 2011
Location: Huntsville, AL
Posts: 631
Thanks: 8
Thanked 24 Times in 21 Posts
Rep Power: 37786
bmrisko has a reputation beyond reputebmrisko has a reputation beyond reputebmrisko has a reputation beyond reputebmrisko has a reputation beyond reputebmrisko has a reputation beyond reputebmrisko has a reputation beyond reputebmrisko has a reputation beyond reputebmrisko has a reputation beyond reputebmrisko has a reputation beyond reputebmrisko has a reputation beyond reputebmrisko has a reputation beyond repute
Re: 89 octane for 5.7 Hemi recommended?

I use the recommended 89. An extra $2-$3 per tank isn't going to kill me.
__________________

__________________
2015 WK2 SRT
Previous Jeeps - '12 WK2 Overland, '99 WJ, '96 ZJ, '93 ZJ (Caged & locked on 35s)
Reply With Quote
  #3  
Old 05-10-2012, 09:51 AM
BuckeyeSRT's Avatar
Senior Member
My Jeep: 2012 5.7L WK2
 
Join Date: Mar 2011
Location: Home of the Buckeyes
Posts: 1,579
Thanks: 28
Thanked 26 Times in 26 Posts
Rep Power: 102281
BuckeyeSRT has a reputation beyond reputeBuckeyeSRT has a reputation beyond reputeBuckeyeSRT has a reputation beyond reputeBuckeyeSRT has a reputation beyond reputeBuckeyeSRT has a reputation beyond reputeBuckeyeSRT has a reputation beyond reputeBuckeyeSRT has a reputation beyond reputeBuckeyeSRT has a reputation beyond reputeBuckeyeSRT has a reputation beyond reputeBuckeyeSRT has a reputation beyond reputeBuckeyeSRT has a reputation beyond repute
Re: 89 octane for 5.7 Hemi recommended?

Very common topic here. Try a search and you will see.
Enjoy your Hemi!
__________________
2012 BB Overland Summit
Like my company on Facebook ...please
https://www.facebook.com/TheSimmondsGroup
Twitter @simmondsgroup
Reply With Quote
  #4  
Old 05-10-2012, 10:36 AM
Member
 
Join Date: Mar 2011
Posts: 499
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 31625
77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute
Re: 89 octane for 5.7 Hemi recommended?

I fill it with 89 and my wife fills it with 87 when she drives it. I notice no difference either way.
__________________
Reply With Quote
  #5  
Old 05-10-2012, 10:55 AM
gaidin43's Avatar
Member
My Jeep: 2014 5.7L WK2
 
Join Date: Apr 2012
Posts: 216
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 1554
gaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond reputegaidin43 has a reputation beyond repute
Isn't it ill-advised to switch octanes back and forth?

So what I'm reading it advised to use 87 in winter and 89 in summer?
__________________

2014 Jeep Grand Cherokee Limited | Max Steel | 4x4 | HEMI | Tow | ORA I | 8.4RA4
Previous Jeeps: 2012 GC Laredo X 5.7L
Reply With Quote
  #6  
Old 05-10-2012, 11:23 AM
Member
My Jeep: 2012 5.7L WK2
 
Join Date: Nov 2011
Location: perry hall, maryland
Posts: 420
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 1647
peckmv has a reputation beyond reputepeckmv has a reputation beyond reputepeckmv has a reputation beyond reputepeckmv has a reputation beyond reputepeckmv has a reputation beyond reputepeckmv has a reputation beyond reputepeckmv has a reputation beyond reputepeckmv has a reputation beyond repute
Re: 89 octane for 5.7 Hemi recommended?

All 89 does is add more anti-knock. It does nothing for mileage. I run 87 all the time with no issues. I do run 89 when I tow. This is because the added strain of the towed load causes the timing to advance and without the added octane knocking will occur, when going up hills.
__________________
Reply With Quote
  #7  
Old 05-10-2012, 10:52 PM
Member
My Jeep: 2012 5.7L WK2
 
Join Date: Sep 2011
Location: Seattle, WA
Posts: 89
Thanks: 2
Thanked 2 Times in 2 Posts
Rep Power: 1192
rushdriven is on a distinguished road
Re: 89 octane for 5.7 Hemi recommended?

I usually fill up at Costco since there is one appox. 3 miles from my house. My only choices there are 87 and 91 octane. I always fill it with 91 octane. When I get as at other stations, I use 89. I seem to get a little better mileage with 91.
__________________
Reply With Quote
  #8  
Old 05-10-2012, 10:54 PM
Member
My Jeep: 2014 3.0L WK2
 
Join Date: Dec 2011
Posts: 6
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 1005
djva076 is on a distinguished road
89 was recommended, and that's what I use. What a lot of people don't realize is that the octane ratings in gas indicate how stable the fuel is under heat and pressure and you don't just select it for better fuel economy.

Higher octane gas remains more stable under a given amount of heat and pressure than lower octane does. Hot running engines with high compression ratios NEED higher octane gas so that it won't detonate before the engine finishes compressing the air and fuel mixture anand feeds it a spark.

Using higher octane fuel in a car that calls for 87 just makes your car have to try and adjust timing for proper detonation. Using lower octane fuel than recommended for your engine makes it run the risk of dealing with fuel that will likely detonate prematurely until/if the computer adjusts timing.

Be nice to your engine and computer and just use whatever the manufacturer says is OK.

Just my 2

-D-

Sent from my GT-N7000 using Tapatalk 2
__________________
Reply With Quote
  #9  
Old 05-11-2012, 08:35 AM
Member
My Jeep: 2012 3.6L WK2
 
Join Date: Apr 2011
Location: Johnstown, PA
Posts: 606
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 1865
Jdsmitty10 is a glorious beacon of light
Re: 89 octane for 5.7 Hemi recommended?

To me, if it calls for 89 but 87 is ok.. using 89 probably gets you the max HP/torque advertised for that engine...running 87 maybe not? im probably wrong...
__________________
2012 Limited V6 4x4 w/20" wheels, lux package, 730N stone white on black. 18% tint on front windows
2012 Toyota Camry SE V6 Loaded
2007 Harley Davidson Softail Deuce
Reply With Quote
  #10  
Old 05-11-2012, 12:35 PM
Member
My Jeep: 2014 3.0L WK2
 
Join Date: Dec 2011
Posts: 6
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 1005
djva076 is on a distinguished road
Quote:
Originally Posted by Jdsmitty10 View Post
To me, if it calls for 89 but 87 is ok.. using 89 probably gets you the max HP/torque advertised for that engine...running 87 maybe not? im probably wrong...
Yeah, I hear ya. That's probably the reason for the recommendation. I'm not sure what the long-term implications would really be of running on fuel that isnt recommended, but is still supported (to an unstated extent).



Sent from my GT-N7000 using Tapatalk 2
__________________
Reply With Quote
  #11  
Old 05-11-2012, 12:40 PM
Member
My Jeep: 2011 5.7L WK2
 
Join Date: Feb 2011
Location: Iowa
Posts: 130
Thanks: 4
Thanked 2 Times in 2 Posts
Rep Power: 1675
CIEGOS has a reputation beyond reputeCIEGOS has a reputation beyond reputeCIEGOS has a reputation beyond reputeCIEGOS has a reputation beyond reputeCIEGOS has a reputation beyond reputeCIEGOS has a reputation beyond reputeCIEGOS has a reputation beyond reputeCIEGOS has a reputation beyond reputeCIEGOS has a reputation beyond repute
Re: 89 octane for 5.7 Hemi recommended?

I always find it ironic that people who get the 5.7L don't worry about how much gas it consumes but rather what octane to put in their gas guzzler in order to save money. If you can't afford the extra 5% more in cost maybe the v6 is more up your alley... just saying
__________________
Reply With Quote
  #12  
Old 05-11-2012, 12:46 PM
Yadkin's Avatar
Senior Member
My Jeep: 2012 3.6L WK2
 
Join Date: Mar 2012
Location: Yadkin Valley, NC
Posts: 1,249
Thanks: 0
Thanked 18 Times in 18 Posts
Rep Power: 202302
Yadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond reputeYadkin has a reputation beyond repute
Re: 89 octane for 5.7 Hemi recommended?

I've had a vehicle before where the OM recommended 89 and had very poor luck with fuel consistency. Apparently stations get 87 and 91 delivered in separate tanks then mix the two at the pump to make 89. So I usually ended up buying 91. I hated having to toss that money out the window so traded in the car.
__________________

__________________
Reply With Quote
Reply

Thread Tools
Display Modes

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
87 or 89 Octane in Hemi? fotomatt1 Engine Performance/Intakes/Exhausts 44 01-18-2012 12:00 AM
Newby-WK Hemi 2005 Follow scheduled maintenance as recommended? oldgeezer Engine Performance/Intake/Exhaust 6 10-21-2011 09:55 AM
Another Hemi Octane Thread whatevrworks Grand Cherokee - WK2 - 20 10-24-2010 08:04 PM
Catch Can Recommended? Chaoul1 Performance Modifications 47 10-13-2010 11:39 PM
Hemi Owners - Gas Octane Question? boarderman23 Grand Cherokee - WK2 - 19 10-03-2010 10:35 AM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 11:32 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community