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Cylinder deactivation? 5.7

raydi07

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Longhorn Laramie 5.7 Hemi w/ E Torque here. First hwy drive yesterday and with just 188 miles on ODO i seen the ECO light come on and noticed a large jump in MPG indicating the cylinder deactivation was on. I was impressed with the quality of the ride, the fuel economy, and just how comfortable this truck is. Keep planning on driving out to the Smokey Mountain area to pick up my RV and bring t home (stored at campground in Townsend TN) but last weekend was snow and ice and this weekend in heavy rain and flash flooding so i guess i wait until next weekend.
Still learning more and more on this Ram. Its not really a daily driver since I have a company car for business so I only get to drive it on weekends. Trip to Fort Hood in Texas from Clarksville TN planned for the holidays then up to Philadelphia to visit my parents so I'll have plenty of windshield time coming up.
 

hessclark

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For those on this thread that mentioned the bogging or exhaust noise during four-cylinder mode, I filled up with 91 octane a few days ago and it has completely gone away. I no longer notice that bogging noise when switching back to eight cylinder mode. You may want to try running higher octane and see if that helps. I can now barely distinguish between four and eight cylinder mode.
 

tdeperte

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2019 Laramie, 5.7. I use 89 octane regular. I don't hear any sound difference in eco mode. In fact the only thing I notice is the eco light and the mpg jump substantially. I'm averaging 18.7 mpg combined. Love this truck.
 
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We've had our truck since Aug and we love it. It is fast, it gets great fuel mileage (15.5 in town/18 highway). This is the first gasser truck I've owned since 1996... all diesel Rams since then. The '96 Ram 5.9L magnum had roller rockers, headers, Mopar HP ECM (had to run 91+ocy), replaced 3.54s with 3.92s...really hot. This truck is hotter and uses 87oct and has 3.21s.

This is interesting reading, I signed up yesterday, and already has been pretty cool.

Cheers, Ron
 

Longhorn5G

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Add me to the list of those that don't notice MDS at all. Not sure if eTorque has anything to do with it.
No etorque here and I dont notice mine at all either, really.

But if I feel frisky, I just turn on Tow/Haul mode and it stays off.
 

Goatmann

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For those on this thread that mentioned the bogging or exhaust noise during four-cylinder mode, I filled up with 91 octane a few days ago and it has completely gone away. I no longer notice that bogging noise when switching back to eight cylinder mode. You may want to try running higher octane and see if that helps. I can now barely distinguish between four and eight cylinder mode.

i have run 87, 89, & 93 octane fuels, i have the ECO light active but don't need it, i know the MDS is engaged by sound and feel especially at speeds lower than 55MPH. i do notice a slight increase in MPG's but man does it sound like crap.
 
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I have a 2019 5.7 with 3.92 gears none torque. I average 13.6 around town and 16.9 cruising at 70. Average on the pedal. I don’t notice a sound difference and wonder if my MDS is even working. Is my fuel mileage just due to the 3.92 gears or?? Thoughts.
 

Goatmann

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I have a 2019 5.7 with 3.92 gears none torque. I average 13.6 around town and 16.9 cruising at 70. Average on the pedal. I don’t notice a sound difference and wonder if my MDS is even working. Is my fuel mileage just due to the 3.92 gears or?? Thoughts.

No data as to mileage on your truck.

If you are over the 3000-3500 miles you should be seeing a bit better overall average fuel economy.
The terrain, the traffic density, and of course the enjoyment of pushing the skinny pedal, will effect MPG’s too.

I see the MDS lamp and know by feel when it kicks in on the flat roads in my area.
 
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I’m right at 2100 miles. I figure my fuel mileage will be lower with the 3.92 gears. But I also feel I should be getting 18-19 on the interstate which I am not
 

Neurobit

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I have a 2019 5.7 with 3.92 gears none torque. I average 13.6 around town and 16.9 cruising at 70. Average on the pedal. I don’t notice a sound difference and wonder if my MDS is even working. Is my fuel mileage just due to the 3.92 gears or?? Thoughts.
I can never tell on mine either. I know some folks can hear/feel it, but I sure as heck don’t, so don’t feel bad. It’s there, don’t worry.
 

SpeedyV

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I have a 2019 5.7 with 3.92 gears none torque. I average 13.6 around town and 16.9 cruising at 70. Average on the pedal. I don’t notice a sound difference and wonder if my MDS is even working. Is my fuel mileage just due to the 3.92 gears or?? Thoughts.
I feel it and see the ECO light kicking on just about every time. I especially notice the little "burp" from the exhaust when it kicks back out of MDS.
 

Granite5thgen

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That neat - then + trick is gonna happen a lot for me. It's not like its noticeable but I know it's there. The gf has no clue but I can tell when it goes from 4 to 8 pretty easily and I only have 185 miles on it so far.
 

NDRam

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For those on this thread that mentioned the bogging or exhaust noise during four-cylinder mode, I filled up with 91 octane a few days ago and it has completely gone away. I no longer notice that bogging noise when switching back to eight cylinder mode. You may want to try running higher octane and see if that helps. I can now barely distinguish between four and eight cylinder mode.

I run 89 and have no issues with noise or performance.
 

Barney556180

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Just got a new Laramie and cannot detect the transitions. Turned on the ECO indicator and still do not notice anything. It is smooth and seamless.
 

Mason1217

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Just got a new Laramie and cannot detect the transitions. Turned on the ECO indicator and still do not notice anything. It is smooth and seamless.
I usually don’t either, but, if you get on a flat road and set the cruise to 43 or 44, it’s right at the on/off point and I can definitely tell when it goes in and out, and the feel/sound is directly related to the “eco” light on the dash. Many people say the eco doesn’t equal MDS, I call bull crap based on my experience they are directly correlated.
 

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