Drag

[Lancer250]

I noticed today that when I'm driving highway speed and let off the throttle the truck looses speed like the brakes are dragging. However, if I'm at highway speed and shift into neutral the truck will coast and not rapidlt loose speed. What is the deal?

[Jonnydime]

Originally Posted by Lancer250

I noticed today that when I'm driving highway speed and let off the throttle the truck looses speed like the brakes are dragging. However, if I'm at highway speed and shift into neutral the truck will coast and not rapidlt loose speed. What is the deal?

Engine braking through the transmission. At highway speeds you are in 5th gear torque converter locked. When the converter is locked there is no slip between the engine and tranny.

[Lancer250]

So I drive into work today, the "drag" is no where near what it was yesterday. The temp is much cooler this morning, If that has anything to do with it. However, yesterday I did bump the toe haul button and it took a couple minutes for me to realize that it was on. After I turned the tow haul off is when I noticed the drag.
Are these diesel trucks affected that much by warmer temps or did I have a glitch from the tow haul being on for a few minutes? Am I a truck hypocondriac?

[Lancer250]

Sorry..........I am not awake yet. Thanks JonnyD.

[jesilvas]

It also depends on wind and other things too.
But if it does it in D but not in N, it's just the compression from the motor helping to slow down the whole truck.