[68RT]

Your Hemi envy would be greater if you had a pre-2008 4.7. I had a 2006 Durango 4.7 and a 2008 Dakota 4.7. The 2008 with the power bump is incredibly better than the earlier version.

Had an 08 4.7 in a 1500 quad cab and a 3.6 in a 2017 1500 crew cab and the 3.6 not only had more power and 6 mpg better in daily driving but 5 mpg better towing with less slowing on steep hills. Also, the 2017 was vastly superior in riding comfort. Getting 23 mpg on the road was easy and with a 25 gallon tank, I only filled up in the morning with 500+ miles a day travel.

 

[68RT]

How do you find the 3.6 for towing? My camper is 5,000 pounds so it is not really pushing it. I'm curious how the 3.6 does.

The hardest tow I had was a Chrysler 200 on a dolly tow with everything we could stuff in it, and the back of the crew cab crammed full and the bed was filled to about two feet above the cab and tarped. The tow was from middle CA to Texas with two in the front seat. Beds, knocked down furniture. Everything they owned was there. Freeway speeds all the way except I slowed to 50 a couple of times on steep grades. When I travel, I never go full throttle because I know the chances of breaking down goes up at full throttle especially when held there for a long time. There are long stretches of nothing for miles on that route and I hate sitting there and being towed. I averaged 16 mpg on that trip.

 

[68RT]

The 4.7 never got a “good” automatic transmission. Even the NAG1 was better.
I know how much the 3.6 performance and economy jumped when it hit the 8speed.

Transmission alone does not account for the 1.1 liter displacement decrease. Engines have taken a huge step forward in efficiency.

 

[68RT]

Yes, but the swap from 5 speed to 8 speed transmission along accounts for about 2 mpg increase behind the 3.6 in the cars (can't do the same comparison in the truck),
And that 5 speed was the NAG1, far better than the transmission behind the 4.7.
I'm fan of the 3.6, but the reality is the 4.7 was hampered by a lame transmission.

The 8 speed is a lot better at being in the right spot during the time getting to highway speeds (45+) but my comparison is when they were at highway speeds. The RPM's at speed are close and should not be that much different in fuel consumption at a constant speed. Both are in overdrive and therefore both are in a planetary drive mode. A very telling difference is the HP of both engines and the 3.6 IS GETTING A LOT MORE OUT OF ITS CUBES.