85 octane

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RDR2019

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Your truck will have knock sensors to prevent damage from mistimed detonation, modern fuel injected engines all have this to respond to varying octane levels and elevation changes. Your truck will likely have a table of values it will resort back to while the lower octane fuel is present and it will clean things up pretty quickly once you move back to the correct octane. Modern FIS are pretty slick in that regard. You can always dump in a bottle of octane booster and/or top things off with a higher octane fuel...or if you are really concerned siphon out the gas and refill the tank with premium unleaded fuel.
 

anothervr6kid

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I have a Gen 1 and got 85 from a Costco in Idaho a few times. I normally run 87 in the truck. From what I read, 85 will act like 87 in high altitudes. I never had an issue with my truck and it drove the same on either fuel.
 

Cory84

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I have a Gen 1 and got 85 from a Costco in Idaho a few times. I normally run 87 in the truck. From what I read, 85 will act like 87 in high altitudes. I never had an issue with my truck and it drove the same on either fuel.

I can't remember the exact details, but at higher elevations your engine does not require the higher octane to prevent detonation. I believe it has to do with lower atmospheric air pressure reducing your compression ratio. I've lived in Idaho and the midwest and never seen anything over 91. My 2017 ran 87 octane with no problems, but my 2020 gets 91. If I were in your shoes, I would be careful doing any long, full throttle pulls with the 85. Then fill it up with 91 and forget it happened.
 

Bob Blessing

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Wow,

I'm a Chemical Tanker Driver and delivered Gas for 5 years but never delivered anything less than 87 Octane. Out of curiosity, what State do you live in?
 

richnot

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Also high octane is not always the best choice, higher does not always mean better performance. The engine has to be built and tuned for it. I know there a lot of people who are going to disagree but read up on it first.

I have a 93 octane tune in my truck because it`s readily available and not $4.25 a gallon (yet) and I could tell the difference from the stock tune and the Gear Heads auto octane auto adjust tune 2.0 , it also had the trans tune at the same time and I had changed to one step cooler plugs.

I bought a full tank (30 gallons) of 93 octane from Sunoco and added 0.44 oz. of Preimum BOOSTane for every gallon of 93 octane, roughly 15oz. The can I bought was 16oz. ($19.99) so I put all of it in and it should have brought my octane level up to 97/98

I could tell you that I did notice a smoother idle and it seemed to be more responsive, this is all subjective and can only be in my head since the truck was never on a dyno to prove the difference



https://boostane.com/about-boostane/boostane-mixing-chart/
 

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