Originally Posted by magnum74
Anyway, had it out in the Rocky Moutains this weekend (Edmonton to Nordegg) and it was great. Pulled grades with no drama on cruise and the way it performed made me confident that throwing 10K behind it wouldn't make me cringe on the same trip.
Thanks for the update. Good Stuff!! Those have been some of my observations too.
Sorry if I get a little winded in this report, but here our my initial observations with 750 miles on my 6.4L. My MDS has come on only very briefly. On the way home from the 240 mile drive from the dealer, on long downhill grade stretches it would come on. A little different hearing for the first few times. EVIC instantaneous mileage would jump up to 25 & 26 mpg, but wouldn't hold very long. Maybe as it gets broken in the MDS will come on more. I'm not expecting too much out of the MDS, this is a HD truck weighing over 7200 lbs with me & my gear in it.
My first tank of gas (funny to say, since I've had a CTD for the last 14 years), was at a hand calc'd 14.4 mpg which was within 2 mpg of where my 2013 CTD (traded off with 7180 miles) was when I traded it. The EVIC tip mileage said 13.8. This first tank was 180 miles with the cruise set at 69mph and 60 miles of 78 mph. I climbed from 4300 feet back up to 7200 feet on the way home, so overall a long uphill grade. My thoughts; The 4.10's was the way to go! The instantaneous mileage doesn't have these big mpg swings the 2013 had with 3.42's. It will hold 14 & 15 mpg on the EVIC on long shallow uphill grade stretches, within 1 mpg of where the 2013 CTD would be.
On the short flatter stretches driving with the cruise set on 78 mph on the interstate, the EVIC would hit & hold 15 & 16 mpg, then drop to 12 & 13 as grades increased. Not to bad and not to different from the 2013 CTD. I never saw better than 15.5 at 75-80mph in the 2013 CTD. Overtime and with more break-in, I believe I'll be within 1.5-2 mpg of where the 2013 was...only time will tell. Still on my 2nd tank of fuel.
The 6.4L does not have the brute torque of the 6.7 CTD...there is that glaring difference. There will be a feeling that the 6.4L is working more when pulling a load then the 6.7 CTD. Will have to expect more shifting, no doubt.
Off road, it is much more nimble than the 2013 CTD 3500 and the extra pounds from the 6.7 CTD is noticeably missing. Lots of forest roads in my area and better off-road handling has been well worth the switch. The 6.4 tuning off the line is much much better than the 2013 CTD. These 4.10's really jump off the line. In low speed, off road conditions it moves the truck when needed, no waiting for the computer nanny to let the CTD rev. What a breath of fresh air. IMO, on a flat stretch there would be very little difference between the 2013 CTD and the 6.4L...up to ~70 mph. The CTD would overtake it from there with the turbo advantage.
Behind town, there is a nice 1000 foot 6% uphill grade that flattens out to 4% for another 400 feet. I like going up there and making sure no carbon builds up...anyways...the 2013 CTD would hit 80 mph at the top. The 6.4L hits 75 mph. The 370 lb/ft less rated torque is the difference. Mind you, this 6.4L has the same gear set as the 68RFE that the 2013 had that I traded. Not too bad for a big heavy gasser at 7200 feet, which is handicapped by 25-30% just from physics of available air.
I have said before on this forum that I thought 2nd gear was a little flat in the 6.4L and I'll still owe up to that. Seems like you have to lean into the throttle rather than pinning it to get that smooth transition. FWIW, on this same hill, my 2001 5.9L CTD stock would hit 62 mph and it pulled everything I ever needed it too with 170 less rated horsepower and just a little more torque.
My towing trips aren't very far where I live, so I can't wait to see how it does. I believe it will fit my needs better than the 2013 CTD did and the main reason why I decided to make the switch so quickly (Big rebates on RAM gasoline engines helped too) One nice thing, this 2014 with coils has a GREAT ride and doesn't shake at speeds over 70 mph like the 2013 3500 CTD I traded off did, it was very annoying and down right uncomfortable at speeds above 75. My only complaint right now is a malfuctioning TPMS, but it seems many owners battle with that system.
Very happy with the switch so far and love hearing 392ci of V-8 HEMI come to life!