Towing with Dodge 6.4

mowin wrote:
In my area, which is rolling hills and some decent "hills", I get 17-18 highway mpg's unloaded if I keep it under 70mph. 6.4 3500 SRW with 3:73's

Same truck but 2500 I get 14-15 with mixed city/hwy. I'm guessing you have less stop/go than me. I've noticed stop/go and idling REALLY kill the mpgs with the 6.4. Also, my area is on winter fuel which seems to hurt me 1-2 mpg. I'm still super happy with the mpg of the truck. 10 years ago an HD gas truck would have been in the 8-10 range for the same conditions (Chevy 8.1, Ford or Ram V10).

In my area, which is rolling hills and some decent "hills", I get 17-18 highway mpg's unloaded if I keep it under 70mph. 6.4 3500 SRW with 3:73's

turtypointbuck wrote:

turtypointbuck wrote:
What mpg could one expect unloaded/no trailer at interstate speeds (75-80 mph)?

Follow-up from a question I posed earlier.
I just got done with a test drive of a Ram 2500 Big Horn Megacab with the 6.4 Hemi and 3.73 gears. No wind. On our interstate going 75 mph the computer read 13 mpg. Salesman said that should go up by at least 2 after it is broken in..??

Here's my mpg on the hwy at 60 mph. VIDEO

I am currently in the process of upgrading from a 1500 to 2500 6.4 HEMI. Glad the people that have them seem happy with them. I have no illusions about gas mileage. However, I am more than happy to trade fuel efficiency for peace of mind knowing that I have a truck under me that will be able to my TT for years to come.

turtypointbuck wrote:

turtypointbuck wrote:
What mpg could one expect unloaded/no trailer at interstate speeds (75-80 mph)?

Follow-up from a question I posed earlier.
I just got done with a test drive of a Ram 2500 Big Horn Megacab with the 6.4 Hemi and 3.73 gears. No wind. On our interstate going 75 mph the computer read 13 mpg. Salesman said that should go up by at least 2 after it is broken in..??

Did you push the reset? It's probably still reading the overall city mpg. My 12 CTD will do the same. If I'm driving around town it'll show 11.5-12. Hit the freeway and it'll take a long time to recalc to the current mpg. Hit the reset once on the freeway and you'll get an instant reading for the current mph. It'll still take a bit to level out. For me it seems like about 5-10 miles and it's locked in.

With that being said I doubt you'll be getting anything great @75mph.

turtypointbuck wrote:
What mpg could one expect unloaded/no trailer at interstate speeds (75-80 mph)?

Follow-up from a question I posed earlier.
I just got done with a test drive of a Ram 2500 Big Horn Megacab with the 6.4 Hemi and 3.73 gears. No wind. On our interstate going 75 mph the computer read 13 mpg. Salesman said that should go up by at least 2 after it is broken in..??

turtypointbuck wrote:

hawkeye-08 wrote:

dreeder wrote:
Your averaging 15.6 MPG's? I must have really gotten screwed or I am doing things horribly wrong, the best average MPG's I ever averaged on my 2012, 2500 with 3.73's was 12.5 hand calculated. That was with a fairly equal mix of city and highway driving.

With the new 6+ speed transmissions, the 4.10 gets better mileage than the 3.73 in many cases. Some with 4.10 have reported 1-2mpg higher with city driving and only slightly better highway than the 3.73... Wish I had ordered the 4.10 on my 2011 GMC 2500HD instead of the 3.73 that I have... with 3.73 gears I have averaged just over 15mpg on a couple of tanks with mostly highway (speeds under 60mph). Freeway tends to be a bit lower, just under 15mpg. City I get 12-13... Towing I get 7.5-8.5mpg at 58-62mph. I might be able to get towing mpg up to 9 if I turn off cruise before any grades or hills..

yes, all hand calculated.

Interesting......I always thought the reason for numerically lower gear ratios eg. 3.73 was to get better gas mileage at the expense of less pulling performance.
So with the 6.4, the 4.1 performs better AND gets better gas mileage?? If true, I need to strongly consider this platform!!

That is more dependent on your driving style and city vs highway percentages. A higher numerically rear gear is not a huge penalty with city driving and and can actually improve it. But highway you will burn more fuel as you will always be turning higher rpms at a steady speed and same transmission gear.

hawkeye-08 wrote:

dreeder wrote:
Your averaging 15.6 MPG's? I must have really gotten screwed or I am doing things horribly wrong, the best average MPG's I ever averaged on my 2012, 2500 with 3.73's was 12.5 hand calculated. That was with a fairly equal mix of city and highway driving.

With the new 6+ speed transmissions, the 4.10 gets better mileage than the 3.73 in many cases. Some with 4.10 have reported 1-2mpg higher with city driving and only slightly better highway than the 3.73... Wish I had ordered the 4.10 on my 2011 GMC 2500HD instead of the 3.73 that I have... with 3.73 gears I have averaged just over 15mpg on a couple of tanks with mostly highway (speeds under 60mph). Freeway tends to be a bit lower, just under 15mpg. City I get 12-13... Towing I get 7.5-8.5mpg at 58-62mph. I might be able to get towing mpg up to 9 if I turn off cruise before any grades or hills..

yes, all hand calculated.

Interesting......I always thought the reason for numerically lower gear ratios eg. 3.73 was to get better gas mileage at the expense of less pulling performance.
So with the 6.4, the 4.1 performs better AND gets better gas mileage?? If true, I need to strongly consider this platform!!

dreeder wrote:
Your averaging 15.6 MPG's? I must have really gotten screwed or I am doing things horribly wrong, the best average MPG's I ever averaged on my 2012, 2500 with 3.73's was 12.5 hand calculated. That was with a fairly equal mix of city and highway driving.

With the new 6+ speed transmissions, the 4.10 gets better mileage than the 3.73 in many cases. Some with 4.10 have reported 1-2mpg higher with city driving and only slightly better highway than the 3.73... Wish I had ordered the 4.10 on my 2011 GMC 2500HD instead of the 3.73 that I have... with 3.73 gears I have averaged just over 15mpg on a couple of tanks with mostly highway (speeds under 60mph). Freeway tends to be a bit lower, just under 15mpg. City I get 12-13... Towing I get 7.5-8.5mpg at 58-62mph. I might be able to get towing mpg up to 9 if I turn off cruise before any grades or hills..

yes, all hand calculated.

dreeder wrote:
Your averaging 15.6 MPG's? I must have really gotten screwed or I am doing things horribly wrong, the best average MPG's I ever averaged on my 2012, 2500 with 3.73's was 12.5 hand calculated. That was with a fairly equal mix of city and highway driving.

I have basically no hills on my daily drive and baby the truck. Don't know what else to say. 5.7l with 4.10's, very very happy with it. At one point I thought I'd keep it for a couple years and move up to a CTD but now I think it will be around for a while.