6.7 Cummins Non DEF vs Newer DEF Trucks

micpib1 wrote:

NC Hauler wrote:

micpib1 wrote:
I had and loved my 5.9 Cummins in my 2001 Ram. I now have a 2013 Ram Longhorn Laramie Limited with the 6.7 and DEF, I use it as my daily driver and I towed my Toy Hauler with it. I live in the mountains, there are no level spots around here. I get 16-17 MPG in the mountains, 20-21 on the highway empty and I averaged 10.5 on my last Quartzsite trip fully loaded with toys and stuff. The 2013 Ram, has tremendous power compared to my 2001 Ram, I ran both completely stock. I have the Aisian(SP) Auto Transmission, I keep my overdrive locked out unless I am running on flat ground and speeds over 65 MPH and I use my exhaust brake most of the time. JH

Why do you "lock out" your OD:h?? I tow in the mountains of WV, TN, NC, SC and VA, and it's RARE that I "drop a gear"....I too have the Aisin tranny . This is the FIRST truck that I could put in cruise control sometimes while towing....When towing, I'm in T/H with EB on "aggressive"...I'm towing a 5er that weighs in at 16,300#..But I've NEVER "locked out" OD gears...I can climb mountains in 5th and 6th at times...doesn't lug and I've gotten as low as 9.5 mpg while towing and gotten "ALMOST" 11 mpg towing this 5er in the mountains. Usally run 62-65 mph...

ON EDIT: Guess I should have noticed the SRW truck, thus 3:42 gearing? But, no more than you're towing...would think that you wouldn't need to "lock out" the OD gears. BUT, seeing as how you're in California, you very well may be in mountains that some would call where I tow, hilly:)

As an "old truck & bus driver" I learned to drive by my Tachometer and Pyrometer as much as my Speedometer. On my Cummins Powered rigs, I used to keep my RPMs between 1450-2100 RPMs to eliminate excessive exhaust temps, I try to keep within the same for my current Ram even though I know it is more forgiving. JH

Understood....I put the truck in T/H and EB on agressive, put in "D" and go...Figure with all the computer technology, the truck is far smarter than I am,:)...so I let it do it's thing...I will put truck in cruise when towing if not in some steep mountains..if I'm in the steeper mountains, I won't use cruise and build speed to take another mountains....the dual radiator cooling keeps this towing machine right where it needs to be...Guess the 4:10 or 3:73 gearing affects the way one tows....Don't know much about the 3:42's....