What fuel for 5.7

[Gman]

You won’t!

I think you may be correct, sir. I haven't noticed anything different thus far.

 

[Barney556180]

As a reference, here’s my 2019 Laramie Sport Crew 4X4 Hemi-no eTorque, 3.21 rear.

On 87 regular unleaded over 850 miles, local driving up to 65 MPG.

 

[JohnUSA]

I get it...85, 87, 89 is centimeter gasoline.

 

[2019REBEL]

As a reference, here’s my 2019 Laramie Sport Crew 4X4 Hemi-no eTorque, 3.29 rear.

On 87 regular unleaded over 850 miles, local driving up to 65 MPG.

When did we get 3.29 gears and I would love to get 65MPG....just not gonna happen in a truck.

 

[SpeedyV]

When did we get 3.29 gears and I would love to get 65MPG....just not gonna happen in a truck.

But wait, I totally get 99 mpg while coasting down the off ramp!

 

[Barney556180]

When did we get 3.29 gears and I would love to get 65MPG....just not gonna happen in a truck.

Yup, should be 3.21 rear: Good eye

 

[ant0064]

You're making the same mistake the OP did. It's like you can't read or just refuse to understand. The labeling doesn't make sense if it doesn't apply equally to everybody. Those labels work only on specific gas pumps. I've proven that with pictures, but some of you are just being purposely obtuse at this point and I doubt you even gave those pics a second look.

So while it may be fine to talk to your sister about buying "plus at the local corner store", it doesn't make sense to request that information in a public forum where everybody's version of "plus" is different or non existant. That was my point. The context of this discussion is a global (or at least North American) location.

Congratulations. You are the most annoying person I have found in these forums so far...attacking people for no reason. You're actually the one who doesn't understand what was being said...the irony. The guy you were arguing with actually had some good points...never once did I hear him say all 89 octane gas is labeled Plus no matter where you go. You just had an overly emotional reaction to someone who was just trying to help people, with gasoline....also never realized octane levels could get someone so mad. Great job.

 

[silver billet]

Congratulations. You are the most annoying person I have found in these forums so far...attacking people for no reason. You're actually the one who doesn't understand what was being said...the irony. The guy you were arguing with actually had some good points...never once did I hear him say all 89 octane gas is labeled Plus no matter where you go. You just had an overly emotional reaction to someone who was just trying to help people, with gasoline....also never realized octane levels could get someone so mad. Great job.

I'm glad to be of service!

As I've said twice myself, the argument was getting petty, I'm not getting drawn into it a second time dude, sorry.

 

[Barney556180]

 

[MG99]

This thread is like something the Bravo Network would turn into a reality show (those of you with wives, girlfriends or sisters will know what I mean). “The Real Ram Drivers of North America” instead of “The Real Housewives of...” (wherever the heck they are now). Sad really.

I read 4 out of 9 pages of arguing and I’m not even sure I got an answer to the question of which octane I should be using.

If I wanted to see people arguing over nonsense I’d actually be watching Bravo with my wife instead of pretending to, while on my phone reading these Ram forums.

 

[Gman]

If you want real drama, check out Lifetime. Spoiler alert: The guy is the guilty party.

Again, the manual still says that the engine was designed for 87-89 octane. For best performance they recommend 89 octane or "Plus".

Where I live, my options are typically 85, 87 (aka "Plus"/mid-grade/Zoom-Zoom), or 91. I've used all 3 and they work fine. Your mileage may vary.

 

[t3p_guy]

If you want real drama, check out Lifetime. Spoiler alert: The guy is the guilty party.

Again, the manual still says that the engine was designed for 87-89 octane. For best performance they recommend 89 octane or "Plus".

Where I live, my options are typically 85, 87 (aka "Plus"/mid-grade/Zoom-Zoom), or 91. I've used all 3 and they work fine. Your mileage may vary.

My area has the same octane options, 85, 87 and 91. I've only ran 85 in mine and haven't had any adverse effects (knocking.) I'm at 6400 miles on it and average 17 mpg. I'm of the school of thought that if it's a normally aspirated engine run as low as you can w/o experiencing engine knock. If it was a turbocharged engine that's a different can of worms.

 

[Gman]

Yep. Turbo and Super charging is a different game and premium fuel is usually required. Normally aspirated engines are usually happy with Regular gas.

The Hemi can be in kind of a grey area with slightly higher compression, which is probably why FCA is one of the few manufacturers that recommends the mid-grade fuels. Some owners might complain about specific conditions that may cause pre-ignition issues with Regular, but folks using the mid-grade are rarely going to have issues, so that's FCA's recommendation.

 

[DTru]

Brand new to this forum and this is my first post. I am coming from the Challenger forums as I own a 13 RT with the 5.7 and it has the same octane recommendations. I owned a 09 and 13 5.7 ram as well and those are where I started getting into tuning.

To answer the OP's question:

Run what you want. You wont "hurt" the engine. You can run 87 for as long as the truck lasts and will probably have no issues due to it.

Now for the detailed performance/MPG based reply.. All 3 of my 5.7 engines saw timing reduction (ST/LT Knock Retard parameter) when running anything less than 93 octane in Texas. When running the recommended 89 octane, my 13 Ram was getting 12 ST and 4 LT. The ideal spot (per reputable tuners like Johan formally head tuner at Diablo etc) is 0-2 ST and 0 LT timing reduction. I manually calculated my MPG on 89 and 93 and the INCREASE in MPG by switching to 93 offset the additional cost of the higher grade fuel as well as reduced timing reduction. It is estimated that each degree of timing is worth 5hp so you should theoretically get more performance. This is NOT saying you gain HP, only that you are getting the HP your engine is rated at. As with any other vehicle each application is going to be slightly different but I have yet to see one 5.7 owner who DOESNT get timing reduction on the recommended 89 octane. Just because you do not hear ping/knock does not mean your engine sensors do not. Just because you have used 87 the whole time and your truck runs "fine", doesnt mean you are not having timing reduction. There are a lot of people who will say that using anything above 87 is a waste of money and that is true for most vehicles, but not the case for the countless 5.7 engines that have data logged.

I have a pretty lengthy write up on a Challenger forum that shows all the steps I took to eliminate timing reduction before getting my tune but I am not sure of the rules on this forum for posting outside links. PM me if you would like.

 

[cotonymopar]

run mid up in the altitude... will try a few tanks of premiums this summer

 

[Willwork4truck]

Appreciate your data Dtru.
The "old school" way was the simply higher the compression, the higher the octane (to a point, anything over 10:1 was pretty much a "premium fuel" motor. It gets a bit more difficult now with higher percentages of ethanol.
I'm avoiding 85 when I see it and trying for the recommended 87-89. In the User Guide (owner's manual), Maintaining Your Vehicle > Fluids / Lubricants section, it says for this engine: "89 octane recommended, 87 octane acceptable, 0-15% ethanol".
I'm not a fuel engineer so I don't know if due to there being less pure gasoline you have to increase the octane (like running E15 at 89 octane) or if it's still ok to run 87.
Since I cannot "hear" pinging or knocking (like old engines used to do alot when under a heavy load), I have to just presume the computer is adjusting the timing correctly, and try to feed the motor a sufficient octane.

 

[ramhead]

This thread is like something the Bravo Network would turn into a reality show (those of you with wives, girlfriends or sisters will know what I mean). “The Real Ram Drivers of North America” instead of “The Real Housewives of...” (wherever the heck they are now). Sad really.

I read 4 out of 9 pages of arguing and I’m not even sure I got an answer to the question of which octane I should be using.

If I wanted to see people arguing over nonsense I’d actually be watching Bravo with my wife instead of pretending to, while on my phone reading these Ram forums.

LMAO!!....Read all 9 pages (so far) and you still won't have an answer.

 

[RodRow]

I make it as simple as possible on myself and pick the middle octane every time I fill up.

 

[Diamondback]

I will let you know once mine has been delivered. On my 5.7 Hemi Durango, I use 89 if 91 isn't available. When I went home to visit my mom in Indiana, they have 93 available .. I tried that and was grinning all the way up and down the street. Of course, that also has SPORT mode with paddle shifters, but even in regular mode, it was a whole new beast.

Others will argue that octane means nothing .. but I know the difference (just ask my Cobra).
I just say, buy what you can afford. If you can try higher octane for a tank or three, do it and see if you like it.
For the mileage I drive daily, I could get away with one of those overly priced electric vehicles

RECOMMENDED is for their stock tune and emissions to pass the EPA standards. (certain counties in Indiana you have to pass emissions prior to obtaining plates, etc.)

Tim N

 

[Jamo237]

Brand new to this forum and this is my first post. I am coming from the Challenger forums as I own a 13 RT with the 5.7 and it has the same octane recommendations. I owned a 09 and 13 5.7 ram as well and those are where I started getting into tuning.

To answer the OP's question:

Run what you want. You wont "hurt" the engine. You can run 87 for as long as the truck lasts and will probably have no issues due to it.

Now for the detailed performance/MPG based reply.. All 3 of my 5.7 engines saw timing reduction (ST/LT Knock Retard parameter) when running anything less than 93 octane in Texas. When running the recommended 89 octane, my 13 Ram was getting 12 ST and 4 LT. The ideal spot (per reputable tuners like Johan formally head tuner at Diablo etc) is 0-2 ST and 0 LT timing reduction. I manually calculated my MPG on 89 and 93 and the INCREASE in MPG by switching to 93 offset the additional cost of the higher grade fuel as well as reduced timing reduction. It is estimated that each degree of timing is worth 5hp so you should theoretically get more performance. This is NOT saying you gain HP, only that you are getting the HP your engine is rated at. As with any other vehicle each application is going to be slightly different but I have yet to see one 5.7 owner who DOESNT get timing reduction on the recommended 89 octane. Just because you do not hear ping/knock does not mean your engine sensors do not. Just because you have used 87 the whole time and your truck runs "fine", doesnt mean you are not having timing reduction. There are a lot of people who will say that using anything above 87 is a waste of money and that is true for most vehicles, but not the case for the countless 5.7 engines that have data logged.

I have a pretty lengthy write up on a Challenger forum that shows all the steps I took to eliminate timing reduction before getting my tune but I am not sure of the rules on this forum for posting outside links. PM me if you would like.

This is great info. Coming from Mercedes, this being my first truck, I’m always tempted to put 93 in my limited. Sounds like what you’re saying is that’s not only safe, but optimal?