Fuel use

[smokedya]

What octane fuel everyone use? I was told to run 92 out here. My truck is an 07 sport 5.7 hemi 4x4.

 

[Harley Harrold]

My owners manual states to use at least 89 octane fuel in my 2007 5.7L HEMI truck. I find my truck runs fine with 89 octane fuel.

 

[05daytona]

I run 87. I honestly didn't see any difference between 87 and 89.

 

[RonJon '06]

I have used 87 octane since day one and never had a problem.

 

[smokedya]

Ok thanks guess I will start saving .50 a gallon now!

 

[MegaMouseGW]

My wifes and daughters truck we run 87 octane in them both, my truck with the V10 in it was detuned so I could use 87, but I normally use 89 octane. Go with whatever the manual says, using a higher grade of gas actually does not do a durn thing.

 

[USMC1188]

I use good ol' #2 hehehehe





But really... I always used premium in my old 05 Hemi

 

[TheSatinPumpkin]

89 when stock/canned tune for 5 years then 91 when going deep into bolt ons.

 

[usaf2006]

I did a tank of 87 and one of 89 and saw no difference. Price is only about .20 different here though.

 

[Rokmonanoff]

87.

Half the stations around here either only have 87, or only have 87 and 89. A couple have premium, but I'm not driving out of my way for premium gas if I don't have a specific reason for it...

 

[M&Ms4D]

I've ran 87 in my 07 for 103k miles now. With a real lack of maintenance on my engine (I know... i feel bad, but after joining the forum i have learned so much), knock on wood i have not had any issues with my hemi.

 

[smokedya]

I just don't want to spend the money on 92 oct.When I can spend almost .50 less a gallon on 87. Plus possibly get better MPG. I will have to listen for it to detonate. I have been courious if it has a tune in it or not,because it dosent have cats and it also has a K&N CAI on it.

 

[hemihustlin]

This is another opinion piece. Whatever you run someone will say the opposite. Run what makes you sleep at night knowing dodge reccomends 89.
What maybe a more important subject is ethanol blend versus non blend. I find i get visibly (on my overhead screen) more fuel economy when using non ethanol blend (91 becauae all 87 around here is 10% ethanol and 89 5% ethanol)
But is it worth the detour to save 10$?
Depends. Obviously i prefer it but i wont go very far out of my way...

 

[BlueRustBucket]

I've started putting 91 (NO ethanol) in my 07. I've experimented with all three octane levels and I got an extra 2-3 mpg with my tuner and premium fuel. Ethanol levels seem to have a big effect as well.

No engine mods or anything either, just my tuner. I run 35" Mudders and I ain't easy on the right pedal

So far....
87 (10% ethanol): 7-9 mpg
89 (5% ethanol): 9-10 mpg
91: 11-13 mpg

 

[usaf2006]

Ive been running 89 for a few months now and am consistently getting 15 mpg per the display. Keep forgetting to hand calc it. Price us usually now around .12 more than 87. I do drive very careful though. I stay under 2k rpms for most of my driving.

 

[Harley Harrold]

I was using 89 octane, but now that my truck is running a performance tune, I am using 93 octane fuel. 19.75 MPG @ 70 MPH. I also change it up when I am down to 3/4 to 1/2 a tank, I will add 89 octane to fill up, then next time it will be back to 93 octane.

 

[dmacell1]

I run 93 octane but only because of the supercharger. My last truck i ran the 89 octane for 10 years without any fuel related problems.

 

[Redtruck-VA]

You don't know how your truck is running without gages to monitor ST/LT fuel Knock. 180 stats and pwr wire both add some timing. Other mods such as LT and free flowing exhaust are mostly compensated for by the PCM. The hemi can stand a lot of abuse. Good luck...

 

[CorDog009]

87. It did run better with the 93 octane tune, but for no more than I do, the 87 tune works fine and saves some $, especially since the truck likes to drink so much gas. The economy 87 tune made it an absolute dog though, killed lots of power and no noticeable increase in mpg.

 

[WulfGang]

IIRC, the diff tween a tankful of 87 vs 93 is approximately $10 at my location.

All I use is 93 now with the DS 93 tune and can never go back to 87 and stock tune. haha