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Another Question On The MDS/ECO Mode

You say that and yet I get 1 MPG better with MDS on. Same route averaged over 5 trips each with and without. Hooray anecdotal evidence.
I'd agree with 1mpg better, but for me the constant struggle then THUMP out of MDS is so damn annoying and can't be good for the engine.
1mpg is not worth it to me for that non stop struggling/thumping. (not to mention the exhaust note change)
 
I've got a solution for ya...trade up to a 2500. It is much smoother in and out of MDS mode, it also shifts at higher RPM which helps it out and prevents the constant kick into MDS, then shift to the next gear and then it instantly kicking back out of MDS. Bottom line, the 2500 6.4 drives much more like a truck should drive than the 1500 5.7 which is tuned for fuel economy.
Of course your mileage will go to crap, but I didn't get the 2500 for the mileage. I'm currently getting around 10mpg where I was around 13mpg previously with my short commute between work and home. Both of those are winter numbers.
 
I've got a solution for ya...trade up to a 2500. It is much smoother in and out of MDS mode, it also shifts at higher RPM which helps it out and prevents the constant kick into MDS, then shift to the next gear and then it instantly kicking back out of MDS. Bottom line, the 2500 6.4 drives much more like a truck should drive than the 1500 5.7 which is tuned for fuel economy.
Of course your mileage will go to crap, but I didn't get the 2500 for the mileage. I'm currently getting around 10mpg where I was around 13mpg previously with my short commute between work and home. Both of those are winter numbers.
Every rig is different. I seldom notice the MDS going from eight to four and back. Really only notice it if I'm paying attention to the light and looking for the change.
 
You say that and yet I get 1 MPG better with MDS on. Same route averaged over 5 trips each with and without. Hooray anecdotal evidence.
I actually don't see any difference. I've been disabling MDS for a few months now as an experiment (tracked with Fuelly since you care about evidence), and don't get any discernible difference in MPG. If you do, good for you man.

Cheers,
 
I do notice that when I have the radio turned up and/or the windows down I don't notice the MDS nearly as much as when I'm driving in silence.
I have a hunch that those of us it bothers the most are also the ones that like to drive in silence. (i.e. windows up / radio off)
 
I've gotten as high as 25 mpg (9.4 L/100 km) on the freeway, sustained over a 3 hour trip, MDS disabled. I really doubt MDS is going to improve that in any way. If MDS would give me even higher numbers, well, I'm happy to forgo that and have a v8 running like a v8 should, without hesitation and jerking when more power is needed.
 
umm, eco mode can't be turned on/off without a tuner, the setting in the display, is just that .. a display of when its on/off...
 
umm, eco mode can't be turned on/off without a tuner, the setting in the display, is just that .. a display of when its on/off...
You can't turn it off permanently without a tuner. You can disable it temporarily by putting the truck in tow/haul mode or using the gear limiter.

Sent from my SM-G986U using Tapatalk
 
2019 Bighorn with an April 19 build date.. tow/haul disables MDS on mine.
 
2019 Bighorn with an April 19 build date.. tow/haul disables MDS on mine.
Tow/Haul disables MDS on all 5.7 Hemi's.
Tow/Haul changes your shift points and makes for a more 'jerky' ride though.
 
Tow/Haul disables MDS on all 5.7 Hemi's.
Tow/Haul changes your shift points and makes for a more 'jerky' ride though.

Ok, from reading some of the earlier posts on this thread it appears that certain 4th and/or 5th gen models don’t disable the MDS with tow/haul. that’s why I posted my build date. Apologies if I’m mistaken.
 
Ok, from reading some of the earlier posts on this thread it appears that certain 4th and/or 5th gen models don’t disable the MDS with tow/haul. that’s why I posted my build date. Apologies if I’m mistaken.
I don’t know about 4th gens, but on 5th gen trucks, tow/haul does disable MDS on all of them.
 
when i get the ECO light on I also notice a vibration through out the truck. wheel, pedal etc. usually under 55 mph
time for dealer to check it out?
 
when i get the ECO light on I also notice a vibration through out the truck. wheel, pedal etc. usually under 55 mph
time for dealer to check it out?

That depends, it this with a stock exhaust? If so, then it's not normal, unless you are really perceptive and can notice the slight change. It could also be your noise cancelling system isn't working correctly.

However, if you have an aftermarket exhaust/muffler, it will be very noticeable when you go into MDS (4-cylinder mode), and even a proper noise cancelling system will not come close to compensating for it. As mentioned, this is why many of us automatically shut off MDS when starting our trucks by choosing 8th gear lockout on our steering wheels or running in tow/haul mode.
 
There are lots of them out there.just google RAM MDS disable
I challenge you to provide a link to an MDS disabler for our 5th generation trucks.
RANGE does not make one.
 
This will differ from truck to truck, some of the biggest factors will be:

1) The octane fuel you are using. The engine will tend to go into ECO/MDS mode more when you are using 89-91 octane fuel since the engine is optimized to run at 89 octane fuel and does not have to advance or retard the timing.

2) The differential that is in your truck. at higher speeds a truck with a 3.21 rear end with have lower RPM's at higher speeds and will be able to go into ECO/MDS mode more often at highway speeds than someone with a 3.92 rear end.

3) Using the cruise control tends to be a little aggressive and the truck will not kick into ECO/MDS mode as often as when you control the gas pedal manually.
 

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