I have done my first highway trip where I was running between 55 and 90 MPH. The Hemi only got 15MPG. I can live with that. The truck seems to like doing between 55 and 60 for the best gas mileage. I have gotten as high as 18MPG.

 

I don't do much highway driving, but when I first got my truck I went on a road trip to pick up some parts. About 2 hours on the highway. The highest I got was 20. Yes, I said 20. Don't ask me how, but I got 20. Averaged about 18 the whole trip. Really surprised me.

Chris

 

The 20 was probably early, when the tank was full?

 

Yesterday we had alot of heavy wind which I'm sure affected the gas mileage. I will compare it to tuesdays return trip home. Hopefully, it will be an easier drive.

 

I have an 04 1500 QC Hemi 4x2 and consistently get 14-15 city and 17-18 highway. Pulling a 5500# boat on the highway at 70 MPH, I get 11.5.

 

With almost 21,000 miles I get about 13 city driving, average high 15s on the highway depending on speed. Taking the state highway with traffic lights produces better mpg than the interstate. I have found I will be in ther area of 20 mpg at 50, 17+ at 65 and lucky to get 15 at 75, but speed feels good to this old man.

No gas saving accessories, but have found two modications that have increased mileage
(1) Changing to Mobil 1 was worth maybe 1/2 mpg, switching to 5w20 over 5w30 quieted (not eliminated ) the hemi tick.
(2) Increasing the psi jin the tires is good for at least a full mpg. The ride is not bad on the regular cab running 44 in the front and 40 in the rear on the 265/70x17. There 140 inch wheel trucks will ride even better.

The above mpg calculations of actual, not the computor. My computor is high by approximately .5 to .8 mpg. Additionally, the cold weather in the northeast cuts about 2 mpgs on short trips

 

https://dodgeforum.com/m_181078/tm.htm

 

04 4X2 Quad Cab with Hemi, and I get about 15.5-17 on highway and about 13-14 city.

 

I have the 4.7 my computer reads 11.5 town on average but shows 22.5 on highway.

 

Wanderer mentions something often overlooked --- Tire Pressure. My tires were all in the low 30s and I pumped them all up to 40 PSI and that alone improved my gas mileage by 1 MPG as well as correcting a slight pull to the right the truck had developed.

Mike