Octane requirements for the 6.4 Hemi???

[JohnandDonna]

My 25 2590 HD says 87 in the fuel cap contracts what I use

I did end up purchasing (had to order it) a 2020 Ram 2500 Limited MegaCab with the 6.4 Hemi and 4.10 rear end. The owners manual for that model year say 87 acceptable but 89 octane is preferred. I use it to tow my 9000 pound travel trailer. I have a bit over 50 thousand miles on it now and have always used 89 octane. Been an awesome vehicle. Plenty of power towing on the flats and up the grades. Makes no sense that they no longer allow you to get the Hemi in the MegaCab.

 

[HarryN]

My 25 2590 HD says 87 in the fuel cap contracts what I use

Welcome to the forum - it is nice to have you here.

It might be worth reading through the hemi tick and lifter problems before holding yourself to that version of fuel.

Only you can decide if it is worth the potential improved mileage, performance and lifespan of using 91 octane fuel and a high additives fuel or not.

The diesel trucks cap says "diesel fuel" but people routinely add additives to the tank for improved operation and lifetime.

IMHO - that 87 rating is just to keep the fleet accountants happy - not what would be better for a normal customer.

 

[HarryN]

I did end up purchasing (had to order it) a 2020 Ram 2500 Limited MegaCab with the 6.4 Hemi and 4.10 rear end. The owners manual for that model year say 87 acceptable but 89 octane is preferred. I use it to tow my 9000 pound travel trailer. I have a bit over 50 thousand miles on it now and have always used 89 octane. Been an awesome vehicle. Plenty of power towing on the flats and up the grades. Makes no sense that they no longer allow you to get the Hemi in the MegaCab.

There are some tow testing youtube posters - such as TFL and JB reviews that ran test of standardized tow setups in UT and on the Ike and high altitudes. The hemi did ok but not nearly as well as other setups in that hot / high condition.

RAM also has to deal with the EPA cafe standards, that attach significant fines / penalties for each vehicle if they miss the fleet average mpg. The diesel pulls that up.

I understand what you are saying though - it would be nice to have a gas engine option. In my mind, it has to be super or turbo charged to compete. Here - I can't drive one tank full of fuel without needing to go up a significant hill and don't want to end up with another vehicle that over heats or can't hold 70 in cruise control.

 

[JohnandDonna]

There are some tow testing youtube posters - such as TFL and JB reviews that ran test of standardized tow setups in UT and on the Ike and high altitudes. The hemi did ok but not nearly as well as other setups in that hot / high condition.

RAM also has to deal with the EPA cafe standards, that attach significant fines / penalties for each vehicle if they miss the fleet average mpg. The diesel pulls that up.

I understand what you are saying though - it would be nice to have a gas engine option. In my mind, it has to be super or turbo charged to compete. Here - I can't drive one tank full of fuel without needing to go up a significant hill and don't want to end up with another vehicle that over heats or can't hold 70 in cruise control.

Except that HD trucks are not part of the EPA cafe standards (that's why they don't even report a MPG figure on the sticker). Also, the standards have been rolled back by the current administration. I have towed through the Smokies out east and the mountains out west. And I have always had plenty of power. Granted I am only towing 9k, plus about 1200 in payload (in addition to 900 lbs tongue weight). With the 4.10 rear end my truck is rated to tow just north of 16k. That said, I would not want to tow much more than 12 -13k. Then it would make sense to go up to a diesel. Also, if I actually needed a diesel (and most don't actually need it) I would get a 3500. Too little payload in the 2500 with the diesel.