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Discussion Starter · #1 ·
Just wanting to get opinions of others that have the MDS HEMI in their Commander.

Can you feel the switch from the 8 to 4 cyl.?

IS there a way to disable this (always run on 8)?


Thoughts/Opinions?
 

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HemiCommander said:
Just wanting to get opinions of others that have the MDS HEMI in their Commander.

Can you feel the switch from the 8 to 4 cyl.?

IS there a way to disable this (always run on 8)?
I have the hemi and cannot tell when it is switching from 8 to 4 or back again.

As far as disabling this...I don't see the advantage of disabling it. The only thing it does is save fuel when cruising down the freeway. I guess you could drive in 4th gear all the time...that should disable it.:D
 

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This is not something I would do because I like MDS but you could probably put a different grade of oil in it and that would shut it off.
 

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Discussion Starter · #4 ·
Guys,

Thanks for the feedback. Thus here is my delima... I CAN tell when MDS kicks in/out...if that is not what I am feeling...then something else is not quite set correct

I drive about 30 miles one way to work - about 1/2 on a 4 lane at 75 MPH and the other on an winding two lane road where, depending on traffic, speed hovers between 55 and 65. It seems that when traveling close to 60 is where I notice it the most...almost as though the system cannot decide if it should be in 8 or 4 mode.

I have to take it in for other issues on 13-July... guess that is one to add to the list for them to check.

Cheers,
Chad

PS: Dispite the several issues (most minor) I really LUV this vehicle. The ride is great, the HEMI tosses me back when I kick it just looks darned good!
 

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I think I can, occassionally, feel it. Kind of like you ran over a single piece of gravel.

Going to 4 cyl, also seems to increase the rpm from 1800 to 1950, which and increase in rpm would make sense. With 4 cyl, you should have the power of a 165 HP engine (half of a 330). Hence increase the rpm to give the same power.

With cruise control and going down hill, as the Jeep seems to be in free fall (almost no engine/drive train, friction), you seem to go to 8 cyl mode, and then downshift to 4th gear. It's trying to keep your Jeep at the preset speed, but it is also bad for the gas mileage. I was upset about that, until I saw the radar at the bottom of the hill <G>.

I would like an idiot light, even if it is aftermarket to tell me when MDS is off or on. Other Chrysler vehicles have it.

Tom
Limited with MDS
 

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Discussion Starter · #6 ·
Tom,

I agree, I too would like to know when the MDS is active. I just returned from a camping trip that took me through very hilly highways ... using the cruise control seems a bit interesting in the way it attempts to maintian speed.
 

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From what I understand and according to the official Jeep Commander literature that explains MDS.... MDS is only active at speeds between 40-60 mph. Thats why you seem to feel the change more at around 60 mph.

I can not feel the switch between 4 cyl operation to 8 cyl operation...its seamless. I useMDS alot when I'm driving on in town highways, I just keep it around 55-59 mph, it does boost mpg...However, MDS seems useless on road trip highway driving as my speedis always higher than the MDS operation speeds.
 

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Discussion Starter · #8 ·
Daytomann - I too rarley use MDS. My commute is 29 miles one way - it consist of about 5 miles through town where the posted speed is 25 mph and then I am on open road with a posted speed of 65mph, to which I generally cruise at 75, for about 19 miles ...the last 5 miles I am in a 55 zone which consist of hills...this is where I seem to notice a slight jolt.

From the replies I am getting I think I really need to have the service dept check this out.

Cheers!
Chad
 
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