67Polara

My Ram has the MDS system and ive been told that turning it off changes the performance of the truck. but i'm curiouse, cause in order to turn it off with out buying a tuner i would switch to tow/haul. would it hurt the truck in any way to drive in the tow/haul mode to rid the MDS system ?

Muswagon

I just wrote about this in the Ram section. In the city, drive in OD/Off. Highway, use Towhaul. It will drive 200% better, more power, smoother, AND better gas mileage which makes zero sense. That was my experience with my POS Ram anyway.

67Polara

thats what made me ask this lol, figured more ppl would see it up here, do you kno if you can switch between the two while driving ?

Muswagon

Yup, I switch all the time at any speed. Sometimes if I stop at 7/11 or something I forget when i get back in, the difference is so incredible that I think for a second WTF is wrong with my truck and then I remember to click the shifter **** and it runs great. Its still a collossal POS tho.

Muswagon

Been driving like this for a year, by the way. Does not cause any issues and it actually the only fix offered by Chrysler. The tech bulletin literally says to turn OD off to correct customer complaints. Make me hate the modern day Chrysler even more. I think it all went south when Cerubus bought it from Mercedes.

67Polara

wow ! what a difference indeed ! switched it to tow/haul and it really comes to life lol pics up alot better and makes the straight pipe sound a bit better =P

really noticed the difference tonight, was on my way into work and went from stop light to stop light with a GMC reg cab short bed, probly around the same year as my Ram, 06. didnt beat him by much but taking size and weight difference into factor still a win none the less =) but i did notice i used alot more gas, dunno if thats just cause of the way i was getting into it or what ;D

Muswagon

Tow Haul in the city will use more gas. Use OD/off for the city, that is the first push of the button, push twice for Tow Haul for highway. Both OD/off and Tow Haul shut of MDS.

It can't be just us that find the MDS useless, makes my truck feel like it is missing off idle. I like the concept, but the execution was shabby

67Polara

mine the opposite of urs lol, push twice for o/d off lol, just thought id throw that out there ha ha, hvnt really payed attention to idle with the mds off but it did idle ruff with it on .

i did some searching on some other forums, and there are other ppl that dont like it, but not for the same reasons. they complain about a droning noise when the mds kicks in, i've noticed it. but it really dsnt bother me on highway speeds radio and road noise drown it out. but cruising down the town streets at 40-45 kicks it in and its rather loud and makes it hard to hold a convo lol

and ppl are questioning what the other 4 cylinders are doing while its on. i've heard a few different things most of them dont make sense tho. that the cylinders continue there function but dont have any oil going to them, also heard that they just sit there and do nothing.

but it really wouldnt make much sense for them to still be moving with no lube... so i'm really hoping there not doing that lol

question tho, does ur engine burn any oil at all ? a friend at a local part store knos a guy that has the same engine as us and his burns about a quart a month.

Muswagon

You are right, once for tow haul twice for OD off, I guess it comes so natural now I dont notice Im clicking twice.

Not sure about oil, I get lazy changes at Mr Lube. However, I am noticing when warm my oil pressure drops when idling, it didnt do that new, and that is a sign of something wearing quicker than it should.

My understanding is the MDS shuts off fuel pressure to those cyliders. Either way, having 4 cylinders not PUSHING down on the crank cannot be good, at least that is what my understanding used to be. As in, when a spark plug or wire goes bad, I was always told a free ride piston is bad, even if it has oil.

67Polara

sounds like it could be seeping through the piston rings, my Polara does that in the summer when i run straight 30, but i put straight 50 in and it's fine. idk that might have somthing to do with it but i think 5w-20's rather light but thats what they call for. as far as what the other pistons are doing i have no idea lol. but if there still in mostion would you need more fuel for the other to make the lazy ones move ?

other great idea/product from dodge =P

Muswagon

My theory on my poor gas mileage when MDS is on during low speed is the same as why when you have an underpowered truck (like my old 78 Toyota mini pickup) and you try and start off in second, gonna buck and cry and use a ton of fuel.

67Polara

i have no doubt that the 5.7 is under powered for my truck, i dont see why youd put a 345 hp ingine in a 7000LBS truck when its unloaded, and with out a driver and or passengers and then shut down half the engine while city driving ? that makes about as much sense as letting a blind man lead you through a mine feild