Veteran
Quote:
hounddogg,Originally Posted by hounddogg
MDS only activates in OD?? WRONG it activates as low as 5/10 mph and as high as 80 mph. Plus anywhere in the middle.This has been discussed before. MDS cuts out four cylinders at any of those speeds under correct conditions and fuel saver light is on.Been like that on my truck since day one.I put my exhaust on in the first 300 miles and can hear when its in four cylinder mode easily.
Go drive your 2009 hemi truck in O/D, then pull the shifter into 5th,
tell me what you felt and heard differently.
You might be confusing the MDS for TQ lock-up. Has a huge effect on what you hear and feel.
When you pull the truck down into 5th, the MDS circut is DEACTIVATED
Also, when you decel, (foot completely off the gas pedal) it shuts off ALL fuel injectors.
That is where you are really saving fuel. But i`m sure you already knew that (????)
Professional
Instead of putting it in tow/haul mode all the time, just put the truck in Electronic Range Select (5) by pressing the (-) button on the shifter and put it in (5) before ever leaving the driveway. Simple as that and MDS will never kick in unless the truck is shut off and restarted. In that case just repeat. Simple solution Dodge built right in and not many people know about. (heck I didn't either until I chatted with a Ram engineer!) Or just buy a Diablo tuner and do away with MDS completely! 
Admin formally known as 94rt10ohio
Just so everyone is not confused the Hemi can go into MDS mode without being in OD.
Record Breaker
Isn't that what I typed/said? I know in tow/haul its deactivated.I never have really messed with the pulling the shifter into 5th thing.
Veteran
Quote:
I'd have your CV joints checked... this is exactly how mine acted when they were going bad. In 2WD things were smooth as glass...Originally Posted by rdculus
I just noticed this vibration on my 2010 crew cab 4x4. Because it only occurs on mine while the 4x4 is engaged at around 70km/h. It feels like I am driving on a continuous set of rumble strips on the highway. There is no way you can miSs it. It vibrates the entire truck.
Champion
Quote:
So, if I am reading this correct, simply using the shift selector does not shut off the MDS, right?
I think you guys are not hearing the mds shuddering I think it's the ESP since you mention snow, when I leave it in 2 wd in ice or snow I get all kinds of grinding and buzzing noises coming from the ESP/ABS keep the wheels moving in a straight line.Originally Posted by autoengmike
2010 Laramie 1500 really notice the shudder now since having to drive around 40MPH in snow. It always happens between 40-45MPH. Shift down to 5 and it is still there. Down to 4 and it downshifts and disappears. I thought the MDS shuts off when taking the transmission out of D and into 5 but it may not. Did not try tow/haul mode though, will try next time on road.So, if I am reading this correct, simply using the shift selector does not shut off the MDS, right?
Veteran
Quote:
Then i would suggest you go try it, you`ll see that i was correct...!Originally Posted by hounddogg
Isn't that what I typed/said? I know in tow/haul its deactivated.I never have really messed with the pulling the shifter into 5th thing.
Also read thread #52, it describes exactly what i was trying to say.
Record Breaker
If in tow/haul or using the select range you are correct.Maybe it was the way of wording.If left in normal drive mode MDS can activate as low at 10/15 mph or at least mine can.I'm driving the Vette today.23 mpg just putting around here running errands and it has 400 horse and no MDS.MERRY CHRISTMAS
Veteran
Quote:
Hmmmmmm, let me see here.... Hemi w/MDS or Chevy w/o MDS....Originally Posted by hounddogg
If in tow/haul or using the select range you are correct.Maybe it was the way of wording.If left in normal drive mode MDS can activate as low at 10/15 mph or at least mine can.I'm driving the Vette today.23 mpg just putting around here running errands and it has 400 horse and no MDS.MERRY CHRISTMAS
my hemi truck is 5200+ pounds of steel and getting 21+ mpg w/400hp
your vette is approx 3200 pounds of plastic w/400hp only getting 23mpg...?
I think dodge HEMI trucks are doing pretty good for mpg for what they are, dont you..?
(and considering 10yrs ago, trucks at best were 1/2 the hp, 1/2 the mpg of today)
Maybe if chevrolet would incorprate MDS type technology like dodge,
vettes might get closer to 35+mpg or more, then i would be impressed.
Anyhow, apples to oranges,
have yourself a very merry christmas too