coobie
Senior Member
- Joined
- Feb 20, 2016
- Posts
- 481
- Reaction score
- 490
- Location
- S.Michigan
- Ram Year
- 2022 Ram 1500 big horn
- Engine
- 5.7 hemi
87 oct in my 6.4 also.Tried 89 oct for 3-4 tanks noticed no difference
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The Owners Manual for my 2017 states, "89 recommended, 87 acceptable". I ran 89 for the first 2 fill ups. Have been running 87 since.
Interesting. The owner's manual for my '16 states -
"6.4L Engine
This engine is designed to meet all emissions regulations and provide satisfactory fuel economy and performance when using high quality unleaded gasoline having a posted octane number range of 87 to 89 as specified by the (R+M)/2 method. The use of 89 octane “Plus” gasoline is recommended for optimum performance and fuel economy.
While operating on gasoline with an octane number of 87, hearing a light knocking sound from the engine is not a cause for concern. However, if the engine is heard making a heavy knocking sound, see your dealer immediately. Use of gasoline with an octane number lower than 87 can cause engine failure and may void or not be covered by the New Vehicle Limited Warranty."
Wish I could find some ethanol free 87
87 oct in my 6.4 also.Tried 89 oct for 3-4 tanks noticed no difference
I ran 87 first cause that's what the dealer put I then I filled with 93 and there's a noticeable difference. Not night and day but if you're paying attention to idle, mds activation and slight throttle response it's definitely there.
I could see a mpg improvement but power would be the same.Pure gas vs E10, big difference. MPG and power improved.