Unloaded City Driving and Tow/Haul

[KHorikawa]

I did a search and really couldn't find an answer. This is while driving unloaded.

To my understanding, the Tow/Haul button for the 48RE is basically the same as OD on/off.

- So by turning ON the Tow/Haul you are turning OFF the OD correct?

- The torque converter is locked with no 4th gear available with the Tow/Haul ON correct? This would be why the engine/trannie provides some braking on a down hill right?

- I drive alot of city stop and go traffic with sometimes hilly terrain. Should I just leave the Tow/Haul ON in the city like I used to with my last gasser with OD on/off button?

 

[BrianWalker]

I city drive with mine "on". With my 4. 10s and O/D off rpms are around 2,200 to 2,500 depending on speed. Seems a little high, a little more "growl", I know it's not hurting anything but some gas mileage.

If I need a little extra power I'll hit the buttom and turn it off instead of putting my foot in it to kick the transmission down.



My old gasser with 3. 55s I drove around town all the time with O/D off until I hit the highway.

 

[CJ8Rockcrawler]

I thought tow/haul changed the transmission shift points/pressure over to a new software map. I believe it actually raises the shift points and increases the hydraulic pressure. At least that's how they work on the Chevy's. (sorry... former bow tie man).

 

[BrianWalker]

That's how I understood a "tow/haul" mode worked.

But the Dodge is just overdrive"O/D", right?



I'll have to do some "seat of the pants" testing to determine if there is a difference.



When pulling my trailer, I do turn the O/D off on some down hills and notice a slight "engine/transmission" braking, if you will. It does hold you back some.

 

[stevenknapp]

On the dodge it turns OD off and keeps the TC locked in 2nd and 3rd. I don't know if it varies the shift points and whatnot.

 

[KCJackson]

The Tow/Haul does change the shift points on the Hemi/545RFE, but not the Cummins/48RE.