2014 Ram 2500 6.4L Hemi

Hello group... i now have 4k miles on my 3500 6.4. Unlike you guys i have good and bad to report. I am currently in California along the coast towing 17k or so (gooseneck ... no worries!). at 200-500 over sea level the truck feels STRONG and it lives in 5th gear unless it hits a hill at which it drops to a nice quiet 4th and chugs right up. At over 2-3k of altitude the power loss is VERY noticeable. going on i40 in AZ from about 4000 ft to 7300 at williams az the truck had to downshift to 2nd gear ALOT. It would stay at the cruise control set 55 most of the time but on the 6-7 percent grades it had to go to second gear at around 40-45 MPH. Overall fuel economy from tx to CA was 9.2 on the display and 8.8 hand calculated. The highs (besides 99 on the display going downhill) were in the flats in TX and CA at around 12 MPG at 60 MPH and the lows were 2-3 going up the 6-7 Percent grades on I40 in AZ. I would consider this a great personal vehicle but i could not use it full time for my business as the fuel range is 200-280 miles altitude dependent towing 17k. The Cummins is 300-350 on the same size tank plus no loss of speed on the uphills so far. I will say that the downhill engine braking was impressive! i had the cruise set at 55 and when it hit 60 it downshifted down to 2nd gear from 5th and held it until the speed hit 55 then it would upshift only when throttle input was needed to keep 55. Again... impressed with this truck for personal use. I could not endorse it for business as ram is trying to pass it for. I will say i am VERY impressed with unloaded MPG... i am right around 20-25 in mix driving. i am about 85% towing mileage so far but the few times i have unhooked the display is averaging around 25! and the range indicator changes accordingly. I think 450-500 is possible with the stock tank at 60MPH. I have to drive back to TX from CA this week with hopefully less weight and ill see how it does. I was at 24k total weight truck and trailer. Not sure how much the truck weights but estimating 7k i was towing a bit over 17k. Again... only had an issue with speed keeping on 5-7% hills on the interstate. I will say that on one backroad i got down to 38 but the hill probably had a 10-12% incline (backroads are not mandated to 7% or less!) and the truck lane had trucks going 5-15MPH so it was not the slowest by any measure. Not to mention lots of broke down vehicles and i was NOT one so that alone made me a happy camper!