I have an 06 Hemi 5.7 w/MDS. I bought it about three weeks ago. I have noticed no increase in gas mileage when I travel on the highway between home/work (20 miles distance one way). I cruise at a steady 70mph.

Is there an easy way to tell if the MDS is indeed functioning? My mpg is roughly 17.

Danke

 

Try a steady 65 mph and see how much of a difference this makes in your mileage. At lower speeds I can hear a low drone sound when the MDS kicks in...but at highway speeds you may not here it. Not to promote another forum...but I found this link on installing an MDS indicator...it looks fairly simple.



Welcome to the forum...I'm a newbie also!

 

I think 70mph is getting to the upper limit of where the MDS will activate. Try it at 60mph a few times you will be surprised at the improvement, I bet.

You can install a light on your dash which will tell you when the mds is on or not. You can find info may places. Here is what I did... http://ceretti.com/mds/


EDIT: Ram TX08, I just noticed our posts are almost identical. Great minds think alike!

 

Hey PhotoRam...I second that!

 

There is a "how to" in our own DIY section for installing an MDS indicator.

https://dodgeforum.com/forum/3rd-gen-ram-faqs-diys-and-how-to-s/163819-mds-active-indicator-light.html


RamTX08: I edited your post slightly. Use the following link & read #7. (Don't lose any sleep over it, I did it a few times when I was a newbie here too.):

https://dodgeforum.com/forum/announcement.php?f=11&a=3

 

Thanks HammerZ71 for keeping us "newbies" in line. I did not know about your post in the DIY section...but its good!

 

I installed the MDS light yesterday and tried it out today (city driving) and was suprised how often it came on.

 

Increase from what? Did you own a different ram and sold it for a MDS hemi?

If you get a catback exhaust you'll hear MDS activate....the light thing works too. My truck is kinda small but MDS on mine will activate at 75 regularly...i've heard it come on going 80 with a tailwind too. The key to getting it to engage and stay on is a slow/steady throttle...sooner or later you'll learn the throttle threshold just from driving around.

And don't use cruise control...everytime I do the MDS constantly kicks in and out even when only going 70mph. The PCM just uses too much throttle to control the speed.

 

Sorry for this retarded question but I bought my '07 used with 3000 miles and I have the window sticker still... any idea if mds is shown on the sticker or how to tell if I have this?

 

If you have a Dodge 1500 series truck with the Hemi engine and it is an '06 or newer and it is not a MegaCab, then you have MDS. It is not an optional feature...