Journey SXT Torque Converter operation affects fuel economy

[Luiggy]

Hello all, from Mexico,

I'm new at this forum, even I'm owner of my DJ since 2011 just decided to sign in, after viewing a lot of posts on fuel consumption and automatic transmission issues, I wanted to join just for sharing some of my experiences.

At first, as many of you I was very disappointed by the fuel performance of my 2.4 DJ just few days after purchase, and after some visits to dealer decided to try to identify by myself why this vehicle with a 2.4 motor has such a fuel and drive behavior, here are my observations and results, you may be able to try on your own vehicle, as these can be tested without any bad impact or concern as you will read next.

At first I've noticed the Automatic transmission (4 shifts) has a software properly matching shift changes to motor rpms, speed, and throttle position, but it seems to have some kind of "bug" in the software, as Torque Converter NEVER LOCKS UP, unless you release the accelerator to allow the rpms to go down by long enough, I consider this is a wrong operation, here is how can you find it, use D position on stick:

- When you are driving at over 35 MPH, you can get the 4th shift engaged, but if you are climbing a hill, torque converter keeps slipping and all you get by depressing accelerator is more rpms, but not much more speed, so your car is just making heat on your AT with the motor power.

-This does not happen if you make the torque converter lockup at 3rd shift, try this: Accelerate between 27~35 MPH, (do not go over 35 as 4th will engage), so once you are around 30, release the accelerator completelly by around 1 second, and then accelerate again as ussually, you will notice Torque Converter is engaged by a drop in the RPMs, at this point you can accelerate deeply and will not lost the lockup state, even over 35 MPH Torque converter will remain locked up when 4th shift is engaged.

- The Abnormal behavior happens only in 4th shift, once it is engaged, if you depress accelerator more, Torque Converter will unlocks and this is why the car starts consuming more fuel, because again you are only getting heat by the Torque Converter slipping, instead of passing power to wheels.

I think correct way to quickly get more power at wheels once you depply depress accelerator, shall be kicking down the AT to 3rd shift to allow motor run at higher RPMs, but not releasing the Lockup in the torque converter and keeping the 4th shift engaged.

After some time doing as a regular practice the Torque Converter lockup on 3rd shift (when possible), I have noticed also that my fuel consumption was reduced by a 15%, before I was getting around 13.5L/100Km (17.4MPG) on combined drive, and with this practice I've got ~11.5L/100Km (20.4MPG), some times even better, also the "feeling" of this lockup is like if car has more power than before.

So if anyone of you guys on this forum may happen to know some Dodge software engineer, please ask him to change the way Torque Converter lockup works, it may improve performance of our DJ in many ways (:->) (by the time I'm posting this, I know new models will have the new DDCT [Double Dry Clutch Transmission], instead of hydraulic AT, so probably our "old" AT will be forgotten soon by even Dodge designers, but who knows, someone may be interested on this as his "improvement hobby").

Best regards...