Octane requirements for the 6.4 Hemi???

[jadmt]

I wonder when they switched. Maybe the manufacturing date determined when they switched over to 87. Mine was made in July and recommends 89.

Mine july 1 of 2020

 

[AnywhereInTX]

Use 87 for everyday driving. If I were to push the engine (can't think of a reason to be thrashing a PW off the redline), I'd try to get the mix to be around the 89. Biggest thing is no codes and modern ECMs will keep the engine safe.

 

[JohnandDonna]

my 2020 owners manual says 87 and no mention of 89. Page 471.

6.4L ENGINE
Do not use E-85 flex fuel or ethanol blends
greater than 15% in this 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 as specified by the (R+M)/2 method.
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 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.

I have a 2020 with the 6.4 and the owners manual says 89 octane is recommended.

 

[H3LZSN1P3R]

91 is ethanol free here so that's what it gets. No ethanol will touch my engines.

I used to believe that too but after actually testing the fuel i have yet to find a local station that actually has 91 that tests how 91 should most endup testing at 89 octane and containing about 5% ethanol

 

[whitexc]

I used to believe that too but after actually testing the fuel i have yet to find a local station that actually has 91 that tests how 91 should most endup testing at 89 octane and containing about 5% ethanol

And we get charged the premium for this so called special blend.

Sent from my moto z3 using Tapatalk

 

[H3LZSN1P3R]

And we get charged the premium for this so called special blend.

Sent from my moto z3 using Tapatalk

The power of marketing

 

[leshawn yazzie]

has anybody try add regular 85 and just add octane boost additive?

 

[LateToTheParty]

has anybody try add regular 85 and just add octane boost additive?

I mentioned it in your other post, but I run 85 all the time. Granted, I'm in Colorado so the altitude allegedly has some impact on how that performs, but I've had no issues following this approach through multiple Hemi's.

 

[ckreef]

We don't have 85 octane where I live. 87, 89, or 93.

 

[60_Driver]

I’ve been running 87 in mine since I got it in November of 2019. Haven’t noticed any issues around town or pulling a 7k lb camper into the mountains of NH & VT. So weird that they have conflicting info online & in print manuals...

Somewhat on the same topic - how bad is Sam’s Club gas? I know top tier brands are the best stuff, but is Sam’s as bad as the El Cheapo stations I used to see in GA?

 

[desert_wagon]

I use 91, and done, 75k truck and now go cheap, bah

 

[mwalsh9152]

I’ve been running 87 in mine since I got it in November of 2019. Haven’t noticed any issues around town or pulling a 7k lb camper into the mountains of NH & VT. So weird that they have conflicting info online & in print manuals...

Somewhat on the same topic - how bad is Sam’s Club gas? I know top tier brands are the best stuff, but is Sam’s as bad as the El Cheapo stations I used to see in GA?

Just about all gas comes from the same depo's these days. The only difference is the additive package that gets mixed in when it is pumped into the truck.

I use 100% Mobil gas in my Caddy because I have a fuel card for work, but aside from that, I always prefer the unbranded stations for the cost savings. Ive never noticed an issue with it. I wouldn't worry about using the Costco gas.

 

[LateToTheParty]

I’ve been running 87 in mine since I got it in November of 2019. Haven’t noticed any issues around town or pulling a 7k lb camper into the mountains of NH & VT. So weird that they have conflicting info online & in print manuals...

Somewhat on the same topic - how bad is Sam’s Club gas? I know top tier brands are the best stuff, but is Sam’s as bad as the El Cheapo stations I used to see in GA?

Costco is part of the TopTier branded family.

Fuel Stations - TOP TIER™

TOP TIER™ Licensed Brands prominently display the TOP TIER™ logo on the pump, pump handle, canopy or in a station window.

www.toptiergas.com

 

[Rockcrawlindude]

Not so worried about the top tier situation but I use 89 exclusively in my truck.

smaller companies get their gas from the same places that big companies do. I worked at Racetrac for years and they’re not a top tier brand but QuikTrip, their main competitor in this market, is. We got all our gas from marathon so we were selling top tier gas, we just didn’t have the logo

 

[Wack99]

Have always ran premium, it runs way cleaner.
When I still had my 04 hemi last year I had to have the heads off for a cam follower swap, the tops of pistons were still as shiney as the day it left the factory.

 

[60_Driver]

Interesting info. Thanks for the replies!