MDS Disable. Why?

[johnny248]

Just wondering why one would want to disable the MDS? Personally I don't see any harm in having it on. At least from my driving, it seems like a nice feature to have kick on while driving on the HWY or whatnot to increase the fuel economy a little bit. I've never seen it activate while doing any sort of hard/semi hard accelerating. What are some reasons that people want to disable it?

[mikel]

Just wondering why one would want to disable the MDS? Personally I don't see any harm in having it on. At least from my driving, it seems like a nice feature to have kick on while driving on the HWY or whatnot to increase the fuel economy a little bit. I've never seen it activate while doing any sort of hard/semi hard accelerating. What are some reasons that people want to disable it?

put an aftermarket exhaust on the truck and the first time it goes into 4 cyl on the highway and sounds like a toyota rice burner, you'll understand

[johnny248]

Just wondering why one would want to disable the MDS? Personally I don't see any harm in having it on. At least from my driving, it seems like a nice feature to have kick on while driving on the HWY or whatnot to increase the fuel economy a little bit. I've never seen it activate while doing any sort of hard/semi hard accelerating. What are some reasons that people want to disable it?

put an aftermarket exhaust on the truck and the first time it goes into 4 cyl on the highway and sounds like a toyota rice burner, you'll understand

Haha I can def hear the difference in the exhaust when the MDS kicks on with my factory exhaust. Almost sounds like a diesel idling. I can imagine that its much worse with some free flowing mufflers. How much decrease in fuel econ is normal with the MDS disabled?

[mikel]

Just wondering why one would want to disable the MDS? Personally I don't see any harm in having it on. At least from my driving, it seems like a nice feature to have kick on while driving on the HWY or whatnot to increase the fuel economy a little bit. I've never seen it activate while doing any sort of hard/semi hard accelerating. What are some reasons that people want to disable it?

put an aftermarket exhaust on the truck and the first time it goes into 4 cyl on the highway and sounds like a toyota rice burner, you'll understand

Haha I can def hear the difference in the exhaust when the MDS kicks on with my factory exhaust. Almost sounds like a diesel idling. I can imagine that its much worse with some free flowing mufflers. How much decrease in fuel econ is normal with the MDS disabled?

some people report little to no loss, depends how much time you spend on the highway....

[stroudtom]

I see about a 1 mpg difference with MDS disabled in town. On the highway there looks to be about 300rpm difference in cruise so I never ran without it unless in a hilly area. MDS sometimes drags on to long going uphill before it kicks off and forces the cruise to kick down to direct, not a pleasant transition. I'm driving a 2011 RAM if that means anything.

tom

[Hemi1014]

MDS routinely gets me 28-30mpg on roadtrips with my Challenger loaded with luggage. I agree that it mostly depends on how much hwy driving you do. I love MDS

[Bradd_D]

Here's why I did it. Well, that and the fact that the car sounds like crap when the MDS engages. I bought a V8 to drive a V8.

[bigwill]

Some want the MDS off do the system over time can cause the "Hemi Tick" which is the cam lobe being chewed up by a hydraulic lifter roller. The oil ports are small in upper engine area of the 5.7 and the MDS is blamed for oil starving that particular lifter and cam lobe. Also, when MDS kicks on, the 4 cylinder mode would cause a drone sound in the exhaust with custom exhaust can too.