Poll- Do you like MDS?

[Burla]

I am surprised so many people like having a complicated mechanical structure and software to shut down 4 of their working cylinders over and over in mid trip. I do respect that position though and I want to thank everyone for participation now and in future. It goes to prove there is a decent amount of support for these types of measures. I would have not thought that, but now I do thanks to these polling numbers. I'd have to say if mine got 3 mpg I would approve as well, but I get better mpg's with it off, most of my trips are local driving. Next long trip I will have to test the mpg's.

 

[2012RAM1500RT]

I am surprised so many people like having a complicated mechanical structure and software to shut down 4 of their working cylinders over and over in mid trip. I do respect that position though and I want to thank everyone for participation now and in future. It goes to prove there is a decent amount of support for these types of measures. I would have not thought that, but now I do thanks to these polling numbers. I'd have to say if mine got 3 mpg I would approve as well, but I get better mpg's with it off, most of my trips are local driving. Next long trip I will have to test the mpg's.

I agree, 3 more mpg, I would have put up with all of the other negatives I had with it. I saw no difference, guess I breathed on the pedal to much. Before any say I drive it to hard I get an honest 18 MPG average on the highway the way I drive which is acceptable to me. My truck looks good, sounds good (yes I have a good sounding exhaust) runs good and drives and rides good so I'm happy without MDS!!!

 

[Mister Luck]

I am surprised so many people like having a complicated mechanical structure and software to shut down 4 of their working cylinders over and over in mid trip. I do respect that position though and I want to thank everyone for participation now and in future. It goes to prove there is a decent amount of support for these types of measures. I would have not thought that, but now I do thanks to these polling numbers. I'd have to say if mine got 3 mpg I would approve as well, but I get better mpg's with it off, most of my trips are local driving. Next long trip I will have to test the mpg's.

Do you have other engine modifications like intake and exhaust ?
What type of oil/ grade are you using and can you tell when you’re a quart low?
I believe fuel grade is a contributing factor also.

I know from experience that I’m in a better power to weight ratio than any year “stock” Tacoma but also getting the same MPG.
This was not the case with our 3Gen brothers and when I had the opportunity to buy my 4G I was looking to match the same with a larger platform the power to weight increase was a pleasant surprise.

I would never look twice at a Toyota product again after owning 4 and having the last (an 09) give something like 23 service recalls. I know previous to 2016 the RAM has had it’s share but I feel my truck to be anything but a lemon.

 

[pacofortacos]

Yep. Flapper actuates during MDS to increase system backpressure. Some guys rip it out, remove resonator, etc., then delete MDS mode via a tuner or manually using gear selector after every engine start. If you leave MDS activated after modding your exhaust, you get a terrible MDS exhaust drone. That's why they decided to add the flapper and resonator - to tune out exhaust drone when MDS is on. I could really hear it on my 2012 half ton and 5.7L Hemi - hated it.

I fit the target demographic - an old fart contractor-type whose noisy exhaust days to attract attention are over. I want a relatively quiet exhaust but with minimal backpressure for maximum drivetrain torque for towing. Since there is debate over MDS system helping or hurting valve lifter lubrication failure issue, I decided to leave exhaust system alone and MDS activated. Originally after joining this Forum, I was all gung ho like many others to upgrade exhaust performance for increased torque. Until I started going down the interrelated rabbit holes.....

I don't think it really actuates, I could look but I thought it was just spring loaded and with the MDS active there isn't enough flow to force it open - probably why it was also so quiet on the 5.7.
I know the flapper is closed by default - ie. on the bench lol.
The flapper in my 6.4 muffler is much larger looking that the one in the picture, unless the picture is deceptive due to it being open.
The one in my muffler is several inches long

 

[retired]

I don't think it really actuates, I could look but I thought it was just spring loaded and with the MDS active there isn't enough flow to force it open - probably why it was also so quiet on the 5.7.
I know the flapper is closed by default - ie. on the bench lol.
The flapper in my 6.4 muffler is much larger looking that the one in the picture, unless the picture is deceptive due to it being open.
The one in my muffler is several inches long

That does make more sense.

 

[bcbouy]

I am surprised so many people like having a complicated mechanical structure and software to shut down 4 of their working cylinders over and over in mid trip. I do respect that position though and I want to thank everyone for participation now and in future. It goes to prove there is a decent amount of support for these types of measures. I would have not thought that, but now I do thanks to these polling numbers. I'd have to say if mine got 3 mpg I would approve as well, but I get better mpg's with it off, most of my trips are local driving. Next long trip I will have to test the mpg's.

i wouldn't say we "like" it,more like we accept it as part of the whole platform and couldn't be bothered to change it.

 

[DA Smith]

The first dealing I had with MDS was on a 2005 Chrysler 300 C that I ordered. I put a magnaflow cat back exhaust system on and that's when the MDS ****** me off. Exhaust sounded great until it shifted into overdrive and then as MDS kicked in and out it sounded like crap. I had to run in fifth gear when cruising or listen to the stupid sound. I've had numerous Ram Trucks since then but left the exhaust stock and the MDS is not detectable with sound or otherwise. I have a 392 SRT8 Challenger with the active exhaust system and it is great. But anytime you do any aftermarket exhaust on a 5.7 or 6.4 Hemi with the MDS you will be unhappy with the sound when going in and out of MDS. From my experience and my view MDS is just mainly BS and is unneeded for the very small amount of fuel it saves.

 

[HEMIMANN]

I don't think it really actuates, I could look but I thought it was just spring loaded and with the MDS active there isn't enough flow to force it open - probably why it was also so quiet on the 5.7.
I know the flapper is closed by default - ie. on the bench lol.
The flapper in my 6.4 muffler is much larger looking that the one in the picture, unless the picture is deceptive due to it being open.
The one in my muffler is several inches long

Don't know but I do know I can't hear when my MDS activates on my 2500 6.4L, and I could easily hear it on my 1500 5.7L.

So something in the 6.4L exhaust quiets the MDS. What % is attributable to the huge muffler, flap valve, or resonator, we don't know without discrete test data.

 

[retired]

Don't know but I do know I can't hear when my MDS activates on my 2500 6.4L, and I could easily hear it on my 1500 5.7L.

So something in the 6.4L exhaust quiets the MDS. What % is attributable to the huge muffler, flap valve, or resonator, we don't know without discrete test data.

maybe it is the in cab noise cancelling system.

 

[stormcom]

All I can say is remember the Cadillac 8 - 6 - 4 in 1981. At least on those, you could put on a switch and turn it on and off.

 

[HEMIMANN]

All I can say is remember the Cadillac 8 - 6 - 4 in 1981. At least on those, you could put on a switch and turn it on and off.

Until it broke, that is. Yet another GM pipedream just like the 350 diesel poorly implemented leading to complete failure and loss of market. Yeah, that.

 

[2012RAM1500RT]

Until it broke, that is. Yet another GM pipedream just like the 350 diesel poorly implemented leading to complete failure and loss of market. Yeah, that.

Oh how I remember those diesels. The headaches I remember working on them, can't think of one good thing to say about them. I remember believing they produced them before doing any testing on them. Now I'm going to try to forget again!

 

[HEMIMANN]

Oh how I remember those diesels. The headaches I remember working on them, can't think of one good thing to say about them. I remember believing they produced them before doing any testing on them. Now I'm going to try to forget again!

Sorry for the "GM Flashback".

Dad thought it was the greatest thing since sliced bread. Being a Great Depression Era guy, "something for nothing" was irresistible to him. So when his company bought some big 'ol Pontiac Bonneville land yachts with GM 350 diesels in 'em, he was astounded at getting 30 mpg when we got circa 13 mpg from our Pontiac LeMans.

Of course, the company LEASED these cars, so their cranks didn't bust in two @ 20,000 miles! It was the next unlucky slob that bought the lease returns that got that privilege! Sure glad those engines started hatching early so he didn't go out and get one for home use!

 

[Hemi395]

Anyone ever had the pleasure of tuning a mid-late 80s electronic QJet? My 87 Monte Carlo I had when I first started driving had one of those lovely carbs in it. Talk about taking something like tuning a carb and making it 107 times more complicated.

Nevermind the rats nest of vacuum lines that surrounded it....

Anyways back on topic, since this is the first winter my new manifolds have seen I'm going to try to remember to shut of MDS using the gear select until the motor is completely warmed up. I'm hoping that will "season" them more evenly.

Probably won't make a difference and I'll end up popping a manifold bolt anyway but it won't hurt to try

 

[Burla]

For the guys liking mds, you know you could have bought a pentastar and got even better gas mileage yes?

 

[2012RAM1500RT]

For the guys liking mds, you know you could have bought a pentastar and got even better gas mileage yes?

Or probably saved a couple grand off the price of your truck when you bought it if it didn't have mds on it!

 

[pacofortacos]

Don't know but I do know I can't hear when my MDS activates on my 2500 6.4L, and I could easily hear it on my 1500 5.7L.

So something in the 6.4L exhaust quiets the MDS. What % is attributable to the huge muffler, flap valve, or resonator, we don't know without discrete test data.

The 6.4 exhaust is much quieter than even the stock single 5.7 exhaust - both the muffler and the resonator are quieter than their stock 5.7 single exhaust brethren. I have interchanged all 4 pieces on my 5.7.

 

[Burla]

6 cylinders on all the time and save thousands off the price of a truck and get 2mpg's better then mds hemi, or mds hemi that shuts down 4 cylinders half the time and sends that gas to the other 4 cylinders? To keep in 100, I think I bought the wrong truck, I'd rather have a pentastar with 3.92s for my use then this garbage mds hemi pos, lol. Hemi tick garbage, i'd never have even tried any other oil then m1. Next thread, hemi versus pentastar, lol. I know the hemi is more popular, but with mds I don't understand why. I tow less the 5k pounds, maybe once in a while more with wood, but nothing over 7.

 

[pacofortacos]

For the guys liking mds, you know you could have bought a pentastar and got even better gas mileage yes?

But it wouldn't pull my boat at 70 mph through the mountains

I have the pentastar in my pacifica, what a pig until 3000+ rpms. I couldn't imagine towing 5000 lbs with one through any hills.

 

[tjfdesmo]

maybe it is the in cab noise cancelling system.

My '15 didn't have ANC.