Switching to 87 octane?

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corneileous

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Ran non-ethanol in my 2020 5.7 for a straight 6 months, 87 octane AND 91 octane. Found no difference between them, and actually slightly better mileage over ethanol gas previously used. Could ell no difference in everyday performance. Did run it on a dyno found here was a 10hp difference, oh well. Now back o ethanol gas as I moved and non-ethanol is harder to find here.
Ethanol blend is just bad for your fuel system components. While gas prices are high right now, I might just give my truck a break from that ethanol 89 and just run 100% 87 in it for a while.
 

turkeybird56

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Well, as a BOIRD, I run 89 in the truck. Almost no non-ethanol in this part of the state, regardless of octane. There are a few "Exxon" stations scatted about that has non-ethanol, not sure on the octane. If I drive for a while to places near a lake I can find non-ethanol more readily available.
 

bm02tj

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The more ethanol the lower the MPG power the same
I run only 87 why waste your money unless you need more power not want more power
 

El_Lobo_Gris1500C

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Just curious exactly HOW much quicker these 5.7L powered crew cab trucks are running a tune with 91-93+ gas vs just running 87 octane gas? Is 2/10ths of a second in a 1/4 mile really worth the $1000 for modules, tunes etc. And spending like $40+ more on every full
Tank of gas? My truck feels plenty quick enough to me running 87 with an intake. Just curious what the actual numbers/facts are.
 
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2012RAM1500RT

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I did my own experiment on my own truck last week while I was on a big trip. I have nothing to gain or loose by not telling the truth in my findings. I have a '12 Ram 1500 with the 5.7 Hemi. 4.10 gears, Vararam CAI, a Diablo sport tuner with a Hemifever 87 and 89 tune on it. MDS delete, speed limiter delete and raised the red line to 6000 RPM. I've had this tuner for about 1 1/2 years and 15,000 miles. I have it on the 87 tune also. I have a camper shell on because we are going on a week long camping trip. Ended up being 2600 miles total. With everything we had for the whole week (which was a load) I guessed we had around 1000 lbs. in pay load. Went from NC to New York on the east side, went west into and through the Adirondack mountains which is absolutely beautiful this time of year. Riding along the US/Canada border, went East over to Niagara Falls. We stopped at more waterfalls than I can count through the Adirondacks. Also around Ithaca and what they call the finger lakes, Watkins Glen, waterfalls everywhere. I ran 89 octane on the first half of the trip and 87 octane on the second half. According to my evic I couldn't tell any difference in MPG. I couldn't tell any difference in performance either. (I know as a mechanic of 45+ years there has to be a difference but it was marginal). I averaged 18.1 MPG by the evic and 17.5 calculating by hand. To me that was great with the load I was carrying, the mountains we were driving in, the stop and go traffic we was in while in the New York city area and the 70 to 75 MPH driving we was doing on the interstate roads. I have now around 140,000 miles on the truck and it never missed a stroke. Tickled to death with my truck and the great time we had on the entire 8 day trip! Hope this may help someone else. As for when it comes to going to the dragstrip........One bumper length is worth it to me! LOL
 
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