87 vs 89 octane.

[‘19ramlveryeha]

So my truck has been making a very specific chirp in gear 4 & 5 at exactly 3k rpm. Initially they blame my exhaust. Had that replaced and original was back on. Now they are saying it’s an engine ping due to me using 87 octane. I know this can’t be the issue but I’ll try it. 89+ from now on and see if that fixes the sound. Anyone else had this issue with the Ram service department blames the fuel used?


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[Scram1500]

Unless something is obviously broken, not much will happen at the dealership. I personally run 93. By the time we squirt the stuff in our tanks it is degrading and losing octane

 

[derp]

So my truck has been making a very specific chirp in gear 4 & 5 at exactly 3k rpm. Initially they blame my exhaust. Had that replaced and original was back on. Now they are saying it’s an engine ping due to me using 87 octane. I know this can’t be the issue but I’ll try it. 89+ from now on and see if that fixes the sound. Anyone else had this issue with the Ram service department blames the fuel used?


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pull obd2. if there;s knock it'll show . heck it can be done in real time.

 

[‘19ramlveryeha]

pull obd2. if there;s knock it'll show . heck it can be done in real time.

I’ll have to get an obd2 reader. Any recommendations.


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[derp]

I’ll have to get an obd2 reader. Any recommendations.


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I bought an ELM327 clone off amazon. Some folks have luck. I did not. I have more patience than money so I then moved on to the MX+. The MX+ was 5x the price but worked straight away and I wanted that so I could focus on the rest of my project.

 

[duke2001]

Unless something is obviously broken, not much will happen at the dealership. I personally run 93. By the time we squirt the stuff in our tanks it is degrading and losing octane

Could you be more specific about the gas at the pump losing octane? How long between manufacture and delivery does this happen? Can you provide references?

 

[Scram1500]

Could you be more specific about the gas at the pump losing octane? How long between manufacture and delivery does this happen? Can you provide references?

I wouldn't rely on me posting links that prove my theory, your own research is your best bet.

Gasoline is constantly evaporating and changing from the moment it is made and tested for purity. Who is to say it was really 87 to begin with? Maybe it was closer to 86.5 but they rounded up. How old is the gas when the tanker gets to the station? How much old gas was in the tanks in the ground when they off loaded? How much moisture has the ethanol in the gas absorbed?

For me personally a tank of gas can be in my truck for 2 weeks up to a month. That could potentially make my gas several months old and the octane will be less than what it started as. Again this is from my own Googling so you may find different results

 

[zlman]

I use 89, that's what Ram recommends and because of youtube. There is a guy on 'tube that has a detailed scanner/computer thing that showed when his 5.7 was retarding knock. 87 showed to do it a lot, 89 some, not sure if he did 93. There was a link in this forum, search and maybe you'll find it.
Maybe I'm throwing $ away on 89 but it makes me rest easy.

 

[Le_Slacker]

I've been using 89, as it seems to be recommended by the manual... I also get better mileage from 'brand-name' gas stations.... the cheaper shops seem to be a bit ****tier.... Shell/Petro-Canada are giving me better range

 

[nilsd]

There was a AAA study on gas quality recently, and results showed significant differences across the spectrum of stations with the ultimate recommendation to stick with one of the Top Tier brands (this is an actual term and they have stickers labeling all their pumps).

I normally find the cheapest 89 I can from a top tier station in town, then sleep easy.

I have observed differences in MPG between 87 and 89, but haven't done the math to see if I break even on 89 bc it wouldn't matter to me anyway.

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[ram0686]

I've recently switched from 87 to 89. Under acceleration, the truck engine note sounds stronger, not that it was straining from 87, it just sounds more stout. Not a real change in performance or mileage in all honesty.

 

[NDanecker]

before I modded I ran 87 and 89. truck ran ok. put a few tanks of 93 in because I had some motor mods requiring the tank to be 93 and after 2 or 3 tanks noticed how much stronger the engine was. not sure on mileage but I bet the ECM pulled timing because of knock which explains more HP TQ according to my butt dyno. is it worth it? up to the individual.

 

[Narg]

I've always burned 89 in the modern V8s I've own from all brands. Just does better in lower ping, and higher MPG. The difference per year is under $100 for most folks, and who wouldn't spend $100 to make their truck run better? Folks spend that much and more all the time with "snake oil" remedies, so why not do it "by the book" in RAMs case, and use what they recommend?

 

[djjr50]

I recently switched from 87 to 89 (I'm on my 3rd tank now) and this thread makes me feel better about that switch. I'll probably keep that up, and also start to run Shell and other top tier brands exclusively.

I've been getting better fuel mileage, but I've also been driving more frugally now that I am use to the latency in the throttle. (month 3 of ownership)

 

[Tellsch]

Good video on this very topic:

Couple things:
1. They are comparing 91 premium to 87, not 89
2. A HEMI is not in the test field
3. Ram recommends 89, but does not require it

Obviously YMMV, but interesting none the less.

 

[ForTehNguyen]

when i first got hte truck i tried out a couple tanks of 87, ran noticeably more sluggish, harder to get the mpg I got on 89. Swapped back to 89 and was noticeably better

 

[NDanecker]

when i first got hte truck i tried out a couple tanks of 87, ran noticeably more sluggish, harder to get the mpg I got on 89. Swapped back to 89 and was noticeably better

try a few tanks of 93.

 

[CornTrucks]

87 octane is explicitly acceptable. If my engine didn’t run perfectly on it I would have it in the shop being fixed under warranty. Sure, there should be marginal performance/mileage gains with the 89 recommendation, but if there’s a problem running 87 octane gas, something needs fixed.

Personally I prefer my 108 octane E85 that I grow myself

 

[Nails]

I’ve ran all 3, noticed a difference each level up. So I’ll stay with 93. Everyone and every truck has their preference.

 

[Scram1500]

Anyone using additives like Lucas? I tried to put some in the other day but the new style filler neck made it a real pain