Better mileage from '05 MDS hemi
Hall Of Fame
Joined: Mar 2009
Posts: 19,168
Likes: 23
From: South GA
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
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
Record Breaker
Joined: Mar 2006
Posts: 2,165
Likes: 2
From: Alberta
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.
Dump the getto 20 in rims and tires ( if you have them ) and run 17in rims and rubber.
Site Moderator
Joined: May 2008
Posts: 9,657
Likes: 24
From: Louisville, Ky
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.
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.
All Star
Joined: Dec 2005
Posts: 809
Likes: 0
From: GA
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
Champion
Joined: Aug 2007
Posts: 4,702
Likes: 2
From: N. Florida
Believe me i have that dam MDS motor, it gets annoying when the motor is using 4 cylinders and you try to pass someone or speed up the reaction is delayed and the engine cranks up couple thousand RPM's and jerks the whole truck.
I have a Superchip but do you know if its bad to turn the MDS off in the truck? I feel like it might mess up the trucks computer.
I have a Superchip but do you know if its bad to turn the MDS off in the truck? I feel like it might mess up the trucks computer.