2016 Ram 6.4 Hemi

[ttavasc]

Originally Posted by Camper_bob

That sounds about right. But now I'm wondering about it. So I'll test it out next time I'm in my truck using the gear selector.

I will say that I'm relatively certain it does not activate when in T/H mode, like you said. But then when I'm towing something, I don't think it would activate normally anyway unless I was going down hill, just coasting. Even going down hill, if I'm in cruise, the engine is braking me slightly (to maintain the set speed), so MDS is not active.

My trailer is heavy enough, MDS would very rarely activate even if it could. My truck is ALWAYS pulling that thing, even down hill! LOL!

I believe this is true for both the 5.7 Hemi in the 1500's and the 6.4 Hemi in the 2500's. I don't think the 5.7 Hemi in the 2500's had MDS. The "ECO" light and MDS are not related though often times you will be in MDS mode when the "ECO" light is on. You can also be in MDS mode without the "ECO" light being on. My understanding is that the "ECO" light comes on when throttle percent is <20%. You can turn the "ECO" indicator off in the Uconnect settings which is often times mistaken for disabling MDS.

Haven't found anything definitive on when MDS kicks in except "when engine load is light" or some other nebulous statement. T/H mode will not disable MDS, however, using the gear selector on the steering wheel does so some folks get in the habit of just hitting Gear+ after starting as it doesn't stick when you turn the engine off.

Admittedly my trailer has smaller frontal area and is fairly light but there were a few times in the flats of Utah where MDS did kick in while towing - I think I got 13.7mpg on that tank (hand-calculated) so from my perspective it works pretty good. Clearly the conditions have to be just right and I'd agree that's usually not when your pulling a wall down the road.

[smurfs_of_war]

My MDS would activate in my 1500 even in tow haul. Of course ONLY when going down hill

Haven't had a chance to check that with my 2500 yet.

[Sledgehammer]

The 1500 and 2500 are possibly different in tow/haul-mds programming.

I seen a Ram engineer post in another forum that Tow/haul will disable MDS on the 6.4 2500. Also locking out 6th gear in manual mode will disable the MDS.

Just what I read on one of those "ask the Ram engineer" chats about the then new 2014 6.4 Ram 2500.

I cant speak about the 1500s, I've only searched about the 2500s.

[SmokerBill]

With my 2011 RAM 1500, tow-haul definitely disables the MDS, as does locking out 6th gear in manual mode. But I guess a lot changes with vehicle models in 4 years.

[Camper_bob]

Originally Posted by Sledgehammer

I wouldn't think mds would activate towing much weight. My trailer weighs about 1500ish more pounds than yours empty so im sure it would never engage with it for sure.

Are you happy with yours towing your 28bhbe?

I'm VERY happy with my combo. The only problem I have is my hitch, but that's a discussion for another thread. Overall, I'm very happy, and my truck has done everything I've asked of it and more. It's one of the best decisions I've ever made.

Originally Posted by ttavasc

I believe this is true for both the 5.7 Hemi in the 1500's and the 6.4 Hemi in the 2500's. I don't think the 5.7 Hemi in the 2500's had MDS. The "ECO" light and MDS are not related though often times you will be in MDS mode when the "ECO" light is on. You can also be in MDS mode without the "ECO" light being on. My understanding is that the "ECO" light comes on when throttle percent is <20%. You can turn the "ECO" indicator off in the Uconnect settings which is often times mistaken for disabling MDS.

Haven't found anything definitive on when MDS kicks in except "when engine load is light" or some other nebulous statement. T/H mode will not disable MDS, however, using the gear selector on the steering wheel does so some folks get in the habit of just hitting Gear+ after starting as it doesn't stick when you turn the engine off.

Admittedly my trailer has smaller frontal area and is fairly light but there were a few times in the flats of Utah where MDS did kick in while towing - I think I got 13.7mpg on that tank (hand-calculated) so from my perspective it works pretty good. Clearly the conditions have to be just right and I'd agree that's usually not when your pulling a wall down the road.

The "ECO" light may only be an indicator, but the change in exhaust note is the dead giveaway; it's VERY obvious. In the 7 months I've been driving my truck, the MDS has never been on without that "ECO" indicator, and the "ECO" indicator has never been on without the MDS. At least that I've seen. I tend to look at the road more than my instrument cluster, so I could've missed it! And I'm relatively certain I've never seen the "ECO" indicator while in T/H mode.

[Tgallagher]

Couldn't stand it any longer. We have been covered up with rain (not griping really), and have been scared of my maiden voyage with the new truck and hitch combo. Did my final inspections and decided to give it a go. Too muddy to do anything else really. Anyhow, here's a few pics.

[Tgallagher]

Side view hitched up with the airbags in trailer mode. I'm thinking the hitch is adjusted a little high. I can't lower it anymore without. Doing some cutting torch action though. I do have another thread going on here about my Reese elite airborne sidewinder.

[ttavasc]

Originally Posted by Camper_bob

The "ECO" light may only be an indicator, but the change in exhaust note is the dead giveaway; it's VERY obvious. In the 7 months I've been driving my truck, the MDS has never been on without that "ECO" indicator, and the "ECO" indicator has never been on without the MDS. At least that I've seen. I tend to look at the road more than my instrument cluster, so I could've missed it! And I'm relatively certain I've never seen the "ECO" indicator while in T/H mode.

I agree with you on the exhaust note for sure - that's how I can tell the MDS has kicked in too. On my 1500 MDS will kick in without the "ECO" light being on - especially on fairly flat freeways.

[Tgallagher]

Another view of the hitch height. Roughly 11" of clearance.

[Tgallagher]

I reset the trip meter leaving my drive. Set the cruise on 65. Tow haul mode. No wind whatsoever. Central Texas rolling plains. Here's the final result.

[Tgallagher]

Retry from the last post.

[Tgallagher]

ran the new hitch thru its paces.

[Tgallagher]

Another hitch pic. I know the companion is not recommended. I am trying it myself. I may regret it, may not.

[Tgallagher]

Good pic. Kinda shows where I have to jackknife after pulling into my driveway to back up under my overhang.

[Tgallagher]

I'm very happy with my hour test drive. Truck towed like a champ. Fuel mileage was less then my 2012 cummins, but not enough to make any regret. The airbags ride great. Hitch is sweet. I am satisfied. If anyone had any questions, lemme kno. I will give the best answer I can.

[Sledgehammer]

Originally Posted by Tgallagher

Another hitch pic. I know the companion is not recommended. I am trying it myself. I may regret it, may not.

Why is the Companion not recommended sir?

Everything looks good btw!

[gtsum2]

Sledge - because he could have two pivot points which would be bad. B&w expressly says to not use that combo

Make sure to double check your hitch often. If it turns on the gooseneck ball, it could be a bad deal. Doesn't look like you have the factory 5th wheel package?

[Tgallagher]

Gtsum2. You do understand it's not on a ball I assume? I get their concern, however the normal stresses and torques of pulling a trailer up a steep hill and stopping seem to be just as much as the possibility of twisting that square insert. I know they are concerned that the designed pivot point could fail and twist the square pin, but the likelihood of that is very slim I think. Just my opinion.

[Big1]

Originally Posted by Tgallagher

Side view hitched up with the airbags in trailer mode. I'm thinking the hitch is adjusted a little high. I can't lower it anymore without. Doing some cutting torch action though. I do have another thread going on here about my Reese elite airborne sidewinder.

Awesome setup, so how do your ram tow it?

[Sledgehammer]

Ahh, I missed the part about the Reese Sidewinder at first.

After having the 6.4 hemi a bit, how do you like it compared to the 6.7 cummins, power wise?