LOL....ok

Its not "bad" to disable the MDS. A lot of guys do it for various reasons including yours. You might get less mileage but you really wont know until you disable it, reset the PCM and fill the tank and then hand calculate your mileage

 

Tire size and rear axle raitos are gonna to more to the bottom line than MDS, any time your over 2000 Rpm the hemi is a thirsty child sucking on the heal of your foot.

Dump the getto 20 in rims and tires ( if you have them ) and run 17in rims and rubber.

 

The MDS doesn't cause the rpm to jump "a couple thousand rpm". When it is engaged, it gains about 300rpm. When I have mine turned on, it pretty much instantly turns off as soon as I touch the throttle. If you are getting big rpm jumps and it takes a lot of throttle to get it to kick out, you have other issues.

It will not mess up the computer to turn it off. it will save the transmission because it won't be constantly partially unlocking the lock-up clutch when it kicks in and locking it back up when it kicks out. I run Mine turned off most of the time because i drive in a 70mph zone daily on my trip to work and it constantly kinks in and out at those speeds.
It's a good concept and works much better on the lighter cars, but the heavy trucks are too hard to keep up too speed on any type of incline so it hunts on and off a lot.

 

I've had it off for three years. The best thing I ever did to my truck was disable that crap. Totally different truck with it off. My 2008 runs as good or better then my 2004 did.

You can disable via the advanced options. Tune truck again and chose advanced tune. Choose tuning level and then choose options. You'll have the MDS Disable selection. Disable, tune. Done.


Sil

 

The switch is 40 milliseconds and is imperceptible. Also, RPM is RPM. MDS by itself won't change it.