4th Gen Ram Tech 2009 - 2018 Rams and the 2019 Ram Classic: This section is for TECHNICAL discussions only, that involve the 2009 - 2018 Rams and the 2019 Ram Classic. For any non-tech discussions, please direct your attention to the "General discussion/NON-tech" sub sections.

Hemi slows down as soon as my foot's off the gas...

Old Feb 2, 2010 | 06:43 PM
  #11  
Zigggy's Avatar
Zigggy
Thread Starter
|
Rookie
Joined: Feb 2010
Posts: 68
Likes: 0
Default

Originally Posted by topgun
Some dumb questions. Is your's a floor or column shifter? You are in Drive and not riding around in one of the other gears? And you're not in Tow Haul mode?

.............................

But I would think if it caused slowing down faster than normal, it would kinda defeat the purpose of saving fuel if you had to press the accelerator sooner to keep moving.
I have the 3.92s too; column shifter and not in tow/haul or any other gear.

I figured it had something to do with the fuel saver but just like you said, wondered if it kinda defeated the purpose if I'm on the gas all the time.
 
Old Feb 2, 2010 | 07:13 PM
  #12  
72combo's Avatar
72combo
Champion
Joined: Dec 2007
Posts: 3,563
Likes: 0
From: Ontario, Canada
Default

Probably got 392 gears and slowing you down faster than a previous vehicle with higher? lower? gear ratio.
 
Old Feb 3, 2010 | 10:43 AM
  #13  
B.Kaiser1's Avatar
B.Kaiser1
Rookie
Joined: May 2009
Posts: 95
Likes: 0
From: North Idaho
Default

As 72COMO stated, it has more to do with the final gear than anything else. The taller the gear the more it will coast.
A 3.92 gear is a realative short gear compared to 3.57's or 3.21's and will not coast much at all.
 
Old Feb 3, 2010 | 11:22 AM
  #14  
wolfmark's Avatar
wolfmark
Rookie
Joined: Jan 2010
Posts: 51
Likes: 0
From: Central Florida
Default

Originally Posted by B.Kaiser1
As 72COMO stated, it has more to do with the final gear than anything else. The taller the gear the more it will coast.
A 3.92 gear is a realative short gear compared to 3.57's or 3.21's and will not coast much at all.
I should add that I immediately noticed a more pronounced coasting deceleration with the Ram than with the '05 Durango Hemi I traded. Both the Ram and the Durango have 3.55 rearends too. I expect it is some combination of drag and friction that is more pronounced in the Ram than it was in the Durango, and after a month of owning the Ram now, barely notice the difference.
 
Old Feb 3, 2010 | 11:45 AM
  #15  
thirtydaZe's Avatar
thirtydaZe
Professional
Joined: Feb 2009
Posts: 114
Likes: 0
Default

Originally Posted by oldjeep
Huh? You let off the gas and you are suprised that the truck slows down? Sounds like every vehicle I've ever driven,
bringing the lulz!
 
Old Feb 3, 2010 | 03:09 PM
  #16  
chrisp929's Avatar
chrisp929
Professional
Joined: Mar 2009
Posts: 153
Likes: 0
From: ny
Default

i'm surprised that no one has suggested that maybe the truck may not be using its highest gear in high speeds. it could be stuck in 4 or something so when gas it let off, the engine braking is more pronounced.

I would suggest taking the truck for a ride and counting shifts to determine if all the gears are being used and the truck in is overdrive when cruising at highway speeds.

I have an almost fully loaded black sport with 20" rims, hemi, and 3.92's and i do not notice any kind of drag on the truck when i let off the gas .. my previous truck was a 1999 dodge dakota with 318 v8 and 3.21 gears ...
???????
 
Old Feb 3, 2010 | 03:33 PM
  #17  
topgun's Avatar
topgun
Captain
Joined: May 2008
Posts: 703
Likes: 0
Default

That's why I asked if she was sure she was in Drive.
 
Old Feb 3, 2010 | 07:38 PM
  #18  
cpelton's Avatar
cpelton
Veteran
Joined: May 2009
Posts: 380
Likes: 0
From: Vancouver, BC
Default

Originally Posted by oldjeep
Maybe he's a former Toyota owner?
lol! good one
 
Old Feb 3, 2010 | 09:22 PM
  #19  
Scotrod's Avatar
Scotrod
Registered User
Joined: Jan 2010
Posts: 24
Likes: 1
Default

Originally Posted by topgun
Mine seems perfectly normal (it's an 09). And that is with the 3.92's.

Same here.


The MDS will not cause your issue. They did add something new to the 2010's though called iDFSO, Interactive Decel Fuel Shut-Off. It is software that cuts fuel to the engine while decelerating to increase gas mileage. .
That's my guess, iDFSO. New for '10.

Question,,, are you 'feathering' the throttle back slightly when you want to maintain/slow down, or are you 'all the way off' when you notice this?

I'm guessing all the way off, and in doing so, I'd 'blame' the 'pronounced feeling of deceleration' on the iDFSO 'fully engaging'.

I can see where that might suck when coming up to stoplights, etc,,,
If you are like me, I try to take full advantage of the 'momentum' of the truck, and 'roll/coast' up to a light,,, (Mr. EZ Duz-it here!)

Come to think of it, I do that by letting off the gas all the way,,, If you have to 'feather' the gas to keep the iDFSO from engaging, I can see where that would be a PITA.

Now, if you were drive more aggressively, and HAUL BUNZ right up to the lights and then slam on the brakes, you'd probably not notice it so much! =)
 
Old Feb 4, 2010 | 08:05 AM
  #20  
bonza's Avatar
bonza
Registered User
Joined: Feb 2009
Posts: 19
Likes: 0
From: Netherlands
Default

It's a standard feature of the 2010 model hemi. When going of the throttle the 2010 model cuts off the fuel injectors to save some extra gas. 2009 and older models keep injecting a minimum amount of fuel when not pressing the accelerator.
 

Thread Tools
Search this Thread

All times are GMT -4. The time now is 07:29 AM.