MDS ?

[Bmags]

I can't/won't speak for anyone towing with the 3.21, not even myself, because I haven't done it, and wouldn't recommend it either, at least not regularly. I have hauled a bed full of top soil once, and firewood three times, I doubt this is anything like towing. Interesting that my truck also came with all the factory "towing" equipment, but so did my 2006 Tacoma (V6 4.0L 3.73). I used that 3 times to tow the 2-axle U-Haul to help folks move. That trailer is 2,000lbs empty, and it was not a problem.

My experience with my 3.21 is the low RPM I see on the highway. In 8th gear at 55mph I'm seeing ~1400 rpm, 65mph just a hair over 1500. At 65mph and dropping back to 7th gear I am seeing right around 1800 rpm. Not exactly the ideal spot on the HP/torque curve, is it?

But I knew I had no plans to tow, and my truck would mostly haul on rare occasion, no off-road plans, mostly commuting and grocery-getting. I thought the 3.21 would be ideal for that and I'm very happy with it. If I bought it for a tow vehicle I would never have settled for the 3.21.

Not sure exactly what is meant by lugging, but if I'm standing still at the entrance to the interstate and push the skinny pedal 3/4 down, I can be doing just under 100mph as I "merge" onto the highway. IMHO that's hauling ass! I like to use tow/haul when I do it. Even with the factory exhaust I love to hear the Hemi "sing".

I run the MDS on at least 99.9%, only turning it off for a moment now and then. And the neat-o tow/haul mode will also lock out the 8th gear for me.

With the gear ratios of the tranny the 3.21 and 3.92 are very close to one another for final drive ratios (essentially the 3.92 gets you an extra low gear, and the 3.21 gets you a second overdrive gear)

So all things the same hauling a load in 5th gear with 3.21 is the same as 6th gear in the 3.92.

I have hauled my cars across several states and horse trailers too (as well as plenty of other heavy equipment). Also installing a gooseneck hitch this weekend… it’s plenty capable, but if I would do it over I’d certainly opt for the 3.92

 

[farout75]

How do I determine if my 2016 Ram 1500 5.7H has MDS feature ?

All 5.7 RAM 1500 had MDS. Frankly I have had 4 RAM 1500 with this MDS and never any issues. Without using it you will drop MPG by one or two MPG at least thats been my test experience.

 

[DonGBaldi]

Interesting discussion but I bought a V-8 for a reason. I want 8 cylinders firing. It keeps my truck from shaking every time it comes off a low RPM. MDS is about as pleasant as those cars that shut off at stop lights and have to start in order to start moving when light turns green. Stupid. Burn another gallon of gas a month and have something drivable.

 

[hallmarc47]

Wow, you guys really get into the details and I don't understant much of it. I'm not a "gear-head" or mechanic specialist. I just get in my Ram and drive it and do servicing when required. I haven't noticed any issues with the MDS; no vibration, etc. But always interesting about the discussion here,

 

[Pjameslamar]

Does anyone have experience with
Edge 32451 Pulsar Tuning modules that has functions to turn off MDS?


Module

 

[Adamcr68]

Does anyone have experience with
Edge 32451 Pulsar Tuning modules that has functions to turn off MDS?


Module

I used a Pulsar for a little while, ended up fouling my plugs early but I kept it in performance mode- mds off all the time.
I switched to a custom tune & have mds turned off, no problems yet, but there is a strong argument here that you actually hurt oil flow by not using it.
Do a search on here & you’ll see a ton of information & opinions, for & against shutting of mds.
I hope to upgrade my cam someday, I would change the lifters at that time to do a true mds delete.

 

[Bmags]

I used a Pulsar for a little while, ended up fouling my plugs early but I kept it in performance mode- mds off all the time.
I switched to a custom tune & have mds turned off, no problems yet, but there is a strong argument here that you actually hurt oil flow by not using it.
Do a search on here & you’ll see a ton of information & opinions, for & against shutting of mds.
I hope to upgrade my cam someday, I would change the lifters at that time to do a true mds delete.

The oil flow argument falls flat once you think about it...

MDS is not active during idle, where the truck as it's lowest oil pressure... So if oil flow was an issue, then we'd see bigger issues and more correlation on trucks that idle often compared to trucks that don't idle much. Not to mention, factory non-MDS engines also suffer from cam failures... so this doesn't add up either.

Driving down the highway, you have tons of oil splash and 50PSI of pressure, I can assure you there is plenty of oil on the cam.

 

[El Guapo Phil]

As for me and my 2016 Ram Big Horn 5.7 Hemi, the MDS does just fine. Going up a hill or grade, the MDS kicks in all 8 cylinders. Cruising on level pavement, the ECO kick in. Never had a problem. When I do tow, I do deactivate the MDS by going manual. Remember, I am in Belize and the roads are not at all like those in Canada and USA. That is why I choose the Ram.