On my 06 I have the gear selector option (and assuming all 3rd gen trucks do as well) for turning off Overdrive and also selecting TOW mode. What are these changing to make a difference...or is it only affecting the transmission?

1. OD on it drops rpms significantly on highway....but stop and go traffic it kills me.

2. Tow Mode- I am guessing it locks out the OD so it wont kick on....what else does it do that is DIFFERENT from just turning OVERDRIVE OFF?

3. OD OFF- same thing...I know it cuts that off....but how is it different from TOW MODE?

 

Tow mode will allow the engine to rev up more RPM's before shifting to next gear and 3rd lockup.
OD off is normal shifting with 3rd lockup but without OD.
OD on is normal shifting and OD lockup.

On the 4 speed auto I would run in OD off in stop and go traffic and under 50 MPH.

 

I have a 03 with the 48re and I never touch the OD button as it never shifts into OD until around 50mph. I never have to touch it even towing up or down hills, it does good on its own.