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When 'coasting', 8 speed noticeably drags

19K views 71 replies 49 participants last post by  Badunit 
#1 ·
I notice that when I remove my foot from the accelerator pedal and 'coast' as I approach a turn, the 8 speed transmission (smoothly) goes into a lower gear which noticeably drags speed down. There is no usual coasting as with all other modern automatics I have driven.
Anyone else recognize this 8 speed characteristic as well?
 
#30 ·
Seems like the the Ram's with 8spd do have DFSO - 2nd bullet to the bottom.

2013 Ram 1500 Features Best-in-class Fuel Economy of 18 MPG City and 25 MPG Highway with Pentastar V-6 and Segment Exclusive Eight-speed Transmissions


  • New 3.6-liter-Pentastar V-6 engine (Ward’s 10 Best Engines winner) with variable-valve timing (VVT) offers best-in-class standard 305 horsepower with 269 lb.-ft. of torque and best-in-class standard fuel economy
  • New V-6 features 42 percent more horsepower, 13 percent more torque and at least 20 percent better fuel economy when compared to the previous 3.7-liter V-6 powertrain
  • 5.7-liter HEMI® V-8 with cylinder shut-off technology and VVT provides 395 horsepower, 407 lb.-ft. of torque and best-in-class fuel economy for V-8 trucks, outpacing even competitive V-6 turbo engines
  • Class-exclusive eight-speed automatic transmission (TorqueFlite 8), standard equipment with 3.6-liter V-6 Pentastar, doubles the amount of gears compared to previously available four-speed automatic transmission to greatly improve fuel economy and contribute to best-in-class standard V-6 towing
  • Coupled with TorqueFlite 8, 5.7-liter HEMI V-8 achieves at least 10 percent better fuel economy when compared to 2012 model
  • New TorqueFlite 8 operated by an innovative dash-mounted, rotary e-shift design
  • The Company’s first application of the new eight-speed with the 5.7-liter HEMI V-8
  • First-in-segment: stop-start system, eight-speed automatic transmission, thermal management system, pulse-width modulated fuel pump and cooling fan, active aerodynamics including grille shutters and air suspension
  • Interactive Decel Fuel Shut-Off (iDFSO) improves fuel economy in both city and highway driving
  • Best-in-class powertrain warranty: 5 years/100,000 miles
 
#32 ·
Did a service at my Ram dealer today.
Spoke with top transmission technician about the 'dragging' problem when foot is lifted off accelerator. Tech states that the drag is primarily caused not by the transmission, but by the engine. The Ram has MDS (Multiple Displacement System) Hemi engines which shut down 4 cylinders when power demand is light or null.

The tech also added that there is 'intelligent' learning in the 8 speed so that it learns to shift best for your type of driving. More downshifting may result.

I drove two other brand new Rams today. One was a Pentastar base model and the other was a LongHorn Hemi. Both shifted and dragged during coasting identically to the way my Ram drives. I am satisfied with the demonstration and tech explanation. I will just learn to live with the 'drag' sensation during coasting. I appreciated the courtesy extended to me by my Ram dealer resolving this question.
 
#33 ·
After reading this thread, I'm a little confused as to what is happening (or why it is happening) in terms of the 8-speed transmission "dragging" on descents. I agree with skytop in that I would also find this characteristic "obnoxious and annoying".
these transmissions downshift the moment you take your foot off the gas. You must drive with your foot on the gas ALWAYS to prevent the OBNOXIOUS and ANNOYING downshifting.
I suppose that on very steep descents, having the transmission automatically downshift would help to save the brakes but on more gradual descents, when I may well want to "coast" to save on gas by not going to a lower gear, I would object for the transmisson deciding for me. Going to a lower gear (higher rpm) when traveling downhill will generally use more fuel than if you stayed in a higher gear and braked judiciously. I mean you can always downshift manually if you see the need. I'd prefer that decision to be mine.
 
#34 ·
Apparently a lower gear with NO fuel usage (iDFSO) is better (more fuel efficient) than a higher gear (normal coastdown) with the engine using fuel. I guess overall it depends on how far you're coasting.

If you don't like DFSO, just shift the trans to Neutral while coasting down (leave the engine running, though!). That's what I do (even on vehicles without DFSO).
 
#35 ·
Addendum: All driving is essentially on flat ground. Now that the dealer tech has given a lucid explanation of the mechanical 'cause' of the dragging effect, I am fine with it.

Transengineer: Go to the trouble each time of putting trans into neutral? I think NOT. It is inefficient waste of time and illegal to drive with vehicle in neutral as you do not have full control of vehicle at that time.

Back to the dealer again to have a small factory dent (from inside pushed OUT) removed by the dent wizard. I am thoroughly unimpressed with the RAM factory inspection methods. In addition to the dent, the weather stripping on my rear d/s door was literally hanging loose when the truck was delivered. Even the dealer missed it. The tail gate emblem that the factory failed to install, finally arrived after almost two months of back order. It will be installed today.
 
#36 ·
Apparently a lower gear with NO fuel usage (iDFSO) is better (more fuel efficient) than a higher gear (normal coastdown) with the engine using fuel. I guess overall it depends on how far you're coasting.

Good point, TransEngineer; though I agree with skytop in that I do not like the idea of "coasting" in neutral and losing a degree of control over the vehicle (for instance, needing to accelerate quickly and having no time to turn the-in my mind- goofy rotary gear selector).
 
#37 ·
Just got my 2014 Sport last week, definitely notice it downshifting but I like it.

Almost acts like its in Tow/Haul mode, only difference is in tow mode my 09 5 speed would grab a gear as soon as I tapped the brake pedal. The new one does it when I get off the accelerator.

Does anyone know if the truck has hill decent assist? I thought I read somewhere that it did, may have been in the settings screen on the truck, I'm wondering if this isn't what we are experiencing???
 
#38 · (Edited)
I agree with Skytop

I agree with skytop it is a really annoying feature to have my new truck feel like it is dragging instead of coasting. At times even when on the accelerator it feels like it is dragging (by this I mean that it feels like it takes more throttle than it should to maintain speed). I have 2014 Outdoorsman with 3.92 gears so the drag feeling might be accentuated by the low gear ratio?. Either way It is something I am not too fond of. With only 1600 mile on my truck I am averaging 12-13 mpg and I was accrediting it to the transmission. I hope my gas mileage will get better as the truck and transmission loosen up.
Have any of you experienced a noise coming from above the key location that sounds like a box of tic tacs being titled, when you shift into or out of park? My service dept. can not find why my truck is doing this. It developed after the truck would not shift out of park. Maybe someone can point me to a thread on this issue.
 
#39 ·
I love the 8-speed transmission. I would have regretted not waiting to look at the 2015 F-150, but they are keeping the six-speed transmission and the Eco Boost engine - both losers in my estimation.

Look for a lot of sponsored criticisms of the Ram 8-speed, the Hemi engine, and the air suspension, since those are all features the F-150 and GM products don't have. Remember the old adage - attack the strength and make it a liability. "Naw, I don't want that 8-speed Ram, 'cause the trannie drags in neutral. Druther have my reliable old six-speed in my F-150." Plant that seed, and if it results in a half dozen potential RAM buyers shifting to another product, it's worth it to them.
 
#40 ·
Maybe the criticism of the 8-speed deceleration behavior has more to do with the local topography. I find the manners of this transmission to be excellent. It's not the fact that it simply downshifts when you let off the throttle, but more importantly, how aggressively it does it depending on the grade. I can control my speed much more easily that GM's crappy 6L80E which is all or nothing and only in tow-haul mode.

This transmission is one of the best features of the Ram IMO.
 
#41 ·
I don't think these complaints are necessarily from pro-Ford trolls. I agree completely... I don't like the "drag" feel (from decel fuel shutoff) either. But remember that Big Brother demands that your vehicle achieve a certain level of fuel economy. If a certain feature irritates drivers, increases vehicle cost, reduces durability, etc. they really don't care. And of course, satisfying Uncle Sam is more important than satisfying the customer.

So if you don't like the "drag", shift into Neutral while you're coasting. It will not "drag" in Neutral. Inconvenient, yes, but I prefer a smooth coast in Neutral to a "draggy" coast in Drive.
 
#42 ·
Last summer I drove a Hemi, 8 speed with 3.92 for a few hours and one of the first things I noticed was the slight drag on coasting. I try to do as much coasting as possible when city driving. I noticed that if I took my foot off the accelerator slowly it didn't seem to drag when coasting, but if I took my foot off more abruptly it would tend to have the drag. I only drove the truck for a few hours so I am not sure this is accurate or across all trucks.

I didn't find it obnoxious, just different and in about 50% of the time the extra slowing in city traffic was a benefit to me. The other times I tended to compensate for it.

All said and done no other light duty truck transmission can compare to the ZF8.
 
#43 ·
I noticed that if I took my foot off the accelerator slowly it didn't seem to drag when coasting, but if I took my foot off more abruptly it would tend to have the drag. I only drove the truck for a few hours so I am not sure this is accurate or across all trucks.
I know I've read somewhere, probably here, that this is what a lot of other drivers are experiencing with the 8 speed transmission.
 
#44 ·
I've never had my 8 speed drag. Its very smooth. I'm glad I have it.
 
#45 ·
ok so this whole thread is rather funny because no body has stated how this dumb feature is saving us gas and GAS is what this is all about.
it is damn annoying to take your foot off the throttle and the brakes are being applied. ... thats of course what it feels like. But has anyone here fully and simply explained why the vehicle is slowed down?
I think its to save gas but how does that really save gas???
Especially when im looking at the mpg gauge and it gets worse after downshifting!! As soon as it downshifts 2 gears I can see the mpg get better when I bump it up 2 gears manually.
so please explain how its possible to get better mpg with the truck slowing?
I really am confused after my experiment by up shifting and getting a faster speed and a better mpg according to the gauges of the vehicle.
Ive had as high as 2500+ rpms without touching the gas pedal!!!!!
 
#46 ·
I suspect this is Decel Fuel Shut Off (DFSO), which cuts all fuel to the engine when the throttle is closed. The fact that the driveline has to keep the engine turning is what gives you the drag. And the trans downshifts earlier than you might expect, to keep the engine speed from falling too low (where it can't recover instantly when you tip back into the throttle).

Since the engine uses NO fuel in this mode, your mileage should actually be infinite (as long as you can keep coasting).
 
#60 · (Edited)
I suspect this is Decel Fuel Shut Off (DFSO), which cuts all fuel to the engine when the throttle is closed. The fact that the driveline has to keep the engine turning is what gives you the drag. And the trans downshifts earlier than you might expect, to keep the engine speed from falling too low (where it can't recover instantly when you tip back into the throttle).

Since the engine uses NO fuel in this mode, your mileage should actually be infinite (as long as you can keep coasting).

I disagree.
All carmakers have been cutting fuel during decal for decades. This is nothing new. It's been done for years with automatics, and with manuals. You make the procedure sound cutting edge for RAM to meet CAFE, but it's old stuff. During a normal decleration, the engine should be in MDS mode, so 4 cylinders are already not injecting fuel.
As long as the engine is already above idle speed ( 700 rpm's? ) there's no fuel savings to be had spinning a fuel-less engine faster. Downshifting will only waste momentum energy.
Beside, The computer can see when the drive hits the brakes. If the driver isn't on the brakes when deceling, there's no "good" reason to downshift.
My guess is Dodge is covering up another issue.
 
#47 · (Edited)
I haven't read all 5 pages of this thread, but I can add that the 8 speed automatic (with the Pentastar V6) that I had in my 2012 Charger did not exhibit this same behavior. I didn't like the dragging during coasting when I first bought my new Ram either, but I've pretty much become used to how it behaves now. I do wish it was like the Charger though as it did not drag during coasting like my Ram does.

Edit: I'll just add that I tend to believe it's likely due to DFSO and not the transmission itself either, since my prior Charger with the 8 speed/V6 did not behave at all in the same way.
 
#49 ·
When I first got my 2014 sport about a month ago the first thing I noticed was the "dragging" when I let off the gas, it almost felt like the brakes were not all the way released. In the last 1000 miles I don't notice it anymore, either it's not doing it anymore or I'm just used to it. That being said, this is the smoothest shifting tranny I've ever driven, I LOVE it!
 
#51 ·
I've noticed it a bit but it's never bothered me. Like others have mentioned, it likely has to do with fuel shut off and with the trans needing to keep the engine spinning.

Plus, I believe the torque converter is locked most of the time. Meaning it's going to act more like a manual transmission in regards to engine braking while lifting off the gas. While this may seem like it's reducing FE by slowing down the vehicle more than may seem necessary, it likely increases efficiency overall.

Overall, this is by far the best transmission I've sampled and I've had several 6 speed autos.
 
#57 · (Edited)
I noticed it when I took one for a test drive. This one had 3.92 gears which probably made it even more noticeable. I actually liked the "engine breaking" characteristic.


My only regrets about my truck is not having the 8 speed and 3.92 gears......
 
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