So MDS doesnt activate with TOW/HAUL button on?

 

Yes, that is correct.

 

When I purchased my Ram, I was specifically looking for an '06 and up for the MDS feature. However, it doesn't seem to have made much of a difference for me. I have a fairly short commute (8 miles each way, about 15-20 minutes). I don't get on the interstate, and I have stop and go traffic. The MDS won't kick on when the truck first starts (even if it's already warmed up).

If you drive long ways, or highway, I could see it making a difference (if you can keep it on). I installed the LED so I can see when it kicks on, and I can drive with it on about 60% of the time if I try, and I get 12.5 MPG (that's granny starts, correct tire pressure, but running 2.5" level).

I would like to get a tuner and disable it, without having to resort to tow/haul mode or O/d off, so that I could get a more apples to apples comparison.

joe
joe

 

I'd hate to act like an idiot but what is MDS?

 

Its a system that "turns off" 4 cylinders on the Hemi 5.7's 2006+ 1500's that is supposed to increase MPG's..
Its undetectable in my opinion-- i cannot tell its enabled or disabled on the highway.... although if I keep my speed lower-- 45-50 mph-- I see a large increase of mpg's...

see link below-

http://en.wikipedia.org/wiki/Multi-Displacement_System

 

Works better on lighter cars, but it does help. At 65 to 70mph speeds, the drag of the large truck trying to cut thru the air causes it to kick on and off quite a bit.
The truck is only rated to get 13 city/ 19hwy anyway, so anything over 19mpg is a gift.
12/18 for a 4x4 with a Hemi.

 

Dang, I have an 03 Hemi so I guess MDS is out of the question for me huh? Unless there's an aftermarket option that I dont know about.

 

Yep no MDS for you unless you swap in an 06-08 Hemi

 

and control modules..

and

and

and...

I think you'd be better off replacing the truck... however, the jury is still out whether its worth it....

 

Ya I don't buy that the OP gets 24 mpg "hand calculated". Maybe on the computer for short durations while mds is active after a reset but I would be highly sceptical that it was for a tank of gas hand calculated. Sorry, not buying it.