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Dodge Ram 6.4 Heavy duty V-8 gas

clarkster
Explorer
Explorer
Says premium gas is recommended?..

What is the downside if regular gas is used?
Some folks are telling me nothing other than a slight decrease in power?..

Ram dealers in my neck of the woods are selling 2500 Ram quad cab 4x4 for $38K.....

I sure could use a boost in ponies towing 5500# travel trailer with a 5.0 Ford half ton.
2006 Dodge 2500 4x4 Laramie crew CTD
2017 Jayco Flight SLX Baja package
18 REPLIES 18

kmbelt
Explorer
Explorer
Mortimer Brewster wrote:
From pg 542 of the manual:
STARTING AND OPERATING 6.4L Engine
This engines is designed to meet all emissions regulations and provide satis- factory fuel economy and performance when using high quality unleaded gaso- line 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.


When I run 87, i get the knocking sound and less power. I just end up running 89 all the time. the cost isn't that much more and the engine runs much smoother.
2014 Ram 2500, 6.4 Hemi, CC, 4x4
2010 Puma 259RBSS

Mortimer_Brewst
Explorer II
Explorer II
From pg 542 of the manual:
STARTING AND OPERATING 6.4L Engine
This engines is designed to meet all emissions regulations and provide satis- factory fuel economy and performance when using high quality unleaded gaso- line 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.
If ethics are poor at the top, that behavior is copied down through the organization - Robert Noyce

2018 Chevy Silverado 3500 SRW Duramax
2019 Coachmen Chaparral 298RLS

DakotaDad
Explorer
Explorer
Had one for a while before moving up to a diesel when we upgraded to a fiver.

I tried to use 89 or 91 when towing, mostly 87 the rest of the time. To be honest, like kzspree, I never saw much difference between the them, whether towing or not. Kept at it mostly for peace of mind.

I liked the truck, and really liked the engine.
Jason, Angie, and our boys, Sean (13) and Liam (8)
Now with Radar and Daisy, both Boston Terriers. Missing Artemus the Labrador, gone on ahead.
2016 Ram 3500 CC Big Horn - 6.7 Cummins - B&W RVK3600 hitch
2015 Palomino Sabre 33RETS Platinum fifth wheel

kzspree320
Explorer
Explorer
I have really have had no problem running 87 octane in my 2016 Ram 2500 with 6.4 hemi and 4.10 rear. I generally run 87 when not towing. When towing my 12K fifth wheel I try to use 89 octane when available. At least one time I can remember no 89 octane was available and I needed gas when towing. I filled with 87 octane and continued towing the fifth wheel. The manual does say 89 recommended and 87 acceptable. I have found no real difference in either performance or mileage. Hope this helps.