87 0r 89 octane

New to the forum. I just bought my first ram(2015 Tradesman) with the 5.7 Hemi and was wondering if you guys are using 87 0r 89 octane.The owners manual says 87 acceptable but 89 recommended.Any advice would be appreciated.

PCM is programmed for optimum performance with 89 Oct.
You can run 87/89/91/93.
If you do any towing-->I would advise running 89 or higher during this time period.

Shell: claims their V-Power (91-93 Oct) fuel has the highest amount of detergents.
They just built & opened a huge truck stop a mile from my house which is actually on my way to & from work. Perfect place to begin fueling up (Fresh Fuel)-(New Tanks)-(Very Busy)!
Anyway before every road trip I will fill-up with the 91 Oct. (Only run 1 full tank of 91 Oct a month) 93 Oct is not available in my area-->Only in the metro.

Prepare for MANY different Opinions/Advice on your question! It is a similar question to asking about ---->what Viscositys of oil to use.
Just attempt to have enough common sense to understand the difference between Recommend & Require!

Just a thought: Even though there are 4 or even 5 octane choices at each pump (Buttons to push).
When you push the button of your Octane choice--->How do we even know we are getting the correct octane that we selected?

I run the so called (recommend) Octane rated fuel along with 5oz-Marine TCW3 @ a 640:1 ratio every fill up & sleep extremely well at night!

Once every OCI I will run 30oz (2)-15oz bottles of Red Line SI-1 through with 3/4 tank of fresh fuel!
Which contains a very large dose of PEA as well as being a excellent UCL.

For (Me) it's only for Piece of Mind as well as a clean fuel system & combustion chamber.
The added plus---> is running a high quality UCL loaded with detergents. (With extremely high hopes this Also adds a dose of lubrication to the fuel pump/injectors. As well as keeping any type of corrosion from forming from effects of the ethanol fuel).

Thanks. I'll use 89 from now on.

I have used 87 octane since new and have had no issues at all and although I haven't keep records over the last 3 year of how many gallons of gas I have used in the 42K now on truck I have saved a nice piece of change.

I know some members will want to start an argument over 87 vs. 89, but all I can tell you, it is working for me.

I use 87 as well. I've tried 89 and 93. Didn't notice any difference except my wallet being lighter.

Interesting points. I had a ford with a 4.6 before my ram and they recommended 87.The owners manual said that running anything higher than that would do more harm than good

Jetsfan122 said:

I use 87 as well. I've tried 89 and 93. Didn't notice any difference except my wallet being lighter.

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Exactly....doesn't make a damm difference lol

I've been running 89 since day one because the owner manual recommends it. I'm guessing you'll get slightly better mileage and power with 89 over 87 since the computer is programmed for it. Whether it's enough to tell a difference I don't know.

Well it has to make a difference, it's science Whether you notice that difference or not in daily driving is the question.

If you pay attention to timing adavance and your knock sensors then it does make a difference between the two but if that info isn't in your face and you let the computer run everything then it doesn't make any difference. Back when I was N/A the difference between 87 and 89 was 4 degrees of ignition retarding at WOT with 87 compared to with 89. This is with a tuned truck however, if you're running stock programming then it's less of an issue since it doesn't run such agressive timing advance. I'd pick up another 4 degrees running the 91 tune and 91 fuel for reference.

What it comes down to is how is the engine being used and does it need the added detonation resistance that the higher octane fuel requires. If it's daily driving then 87 is perfectly fine, towing or performance driving then I wouldn't hesitate to use 89. If you run a tuner then you NEED to run whe octane it's tuned for.

I run 93, should've done it a long time ago. You will extend the life the if you run recommended vs. 87.

i ran both 87 and 89 for long periods. 89 definitely feels stronger and smoother than 87 with the factory tune and with a hemifever Diablo tune. I now run 93 with a hemifever tune, but I'd definitely recommend 89 for a stock truck.

Lenbob2004 said:

New to the forum. I just bought my first ram(2015 Tradesman) with the 5.7 Hemi and was wondering if you guys are using 87 0r 89 octane.The owners manual says 87 acceptable but 89 recommended.Any advice would be appreciated.

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If I remember correctly before I bought my Diablo Sport Tuner...giggity....lol, truck seemed to like the 89 much better than the 87. Plus I got a little bit better mileage, too. Course, this is on a 2008 Ram although I can't imagine the results as far as just an increase alone would be much different on your 15.

Besides, another thing to consider, when the manual (mine for my 08 says it too), that even though 87 is acceptable but 89 is preferred, that pretty much tells me that I really don't want to run 87 if I want the full potential outta my motor on factory program. Basically they're just saying that 87 will work without pre detonation pinging and won't void your warranty if you use it.

SyN said:

PCM is programmed for optimum performance with 89 Oct.
You can run 87/89/91/93.
If you do any towing-->I would advise running 89 or higher during this time period.

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If you read your manual, it's on page 628 for the 2015 Rams, even says the same thing for my 2008 that the use of premium or anything higher than 89 is not recommended. In my opinion it's most likely because the PCM would have to be programmed to run on anything higher. Mine has...lol. I regularly run 91 in mine.

Run 89 or 91 in mine.

Lenbob2004 said:

Interesting points. I had a ford with a 4.6 before my ram and they recommended 87.The owners manual said that running anything higher than that would do more harm than good

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Hmm, must be a Ford thing I guess, Lol. It's been proven many times that using hotter fuel than what the book calls for isn't going to affect anything except your bank or cash balance.

Lotta people will try to convince you otherwise, tho.

I'm not sure how all stations refine/blend their fuel...Around here the Exxon/Mobil 89 octane does NOT come from the refinery...It is a mix of the 87 octane tank and the 91 octane tank right at the local gas station...Who says the pumps are mixing the EXACT amount of each fuel...So in my opinion the 89 is just a crap shoot if your really getting what they say...That's why I either use 87 or 91... That I feel has a better shot at being the true octane, since those both come from the refinery...My truck could care less which fuel I use when not towing, nothing noticeably different...91 octane does give me a slight increase in hwy mileage when towing...But not enough to offset the added cost...

my old 1999 magnum hated 87 oct, running under load it sounder like marbles rattling around under the valve covers. put 93 oct in the old girl and she would purr.

There's actually a few stations around where I live that carry ethanol free 91. I run it in my boat,lawnmower etc. I've seen some stations elsewhere that have 89 ethanol free.

SHOOT2KILL said:

I'm not sure how all stations refine/blend their fuel...Around here the Exxon/Mobil 89 octane does NOT come from the refinery...It is a mix of the 87 octane tank and the 91 octane tank right at the local gas station...Who says the pumps are mixing the EXACT amount of each fuel...So in my opinion the 89 is just a crap shoot if your really getting what they say...That's why I either use 87 or 91... That I feel has a better shot at being the true octane, since those both come from the refinery...My truck could care less which fuel I use when not towing, nothing noticeably different...91 octane does give me a slight increase in hwy mileage when towing...But not enough to offset the added cost...

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I think a lot of gas stations use that technique. It just doesn't make sense to put three big ole tanks in the ground when you can just use two blend it. Besides, that's a lot less fuel that has to be bought and keeps the fuel fresher since 87 is the almost always more popular choice anyways.

On a side note, I would hope that since blending is extremely common that there's standards in place to make sure it's getting blended properly.