resistance/drag when let off gas?
 

Occasionally, when I let off the gas, the car will slow down from resistance almost as if I had put on the brakes.
Other times, it's free and clear.

Anyone experienced this? Transmission? Brakes?

yes, this has been discussed alot. Of course it never happens when I bring it to the dealer.

i think this is called engine braking? this happens in my merc as well

You can get this effect if you have left the cruise control on. e.g. if you had the cruise control on at say 40mph and then you accelerate up to 70mph, when you llift off the gas the car will think you want to go back to 40mph and apply the brakes.

Or maybe the tranny is in sport, or thinks you want to drive in a sporty fashion, and is holding a lower gear? The tranny is adaptive so if you've been acceleration and braking hard, it will tend to hold a lower gear.

its a programming issue

I've definitely noticed it in sports and assumed it's the way it's supposed to work. It doesn't seem to do it in regular trans mode. At least not as much.

it does it in both modes for me.

I notice it to in my 10/06 Build 4.8. I thought I was crazy, but we'll see.

Chris

Its the transmission. In sport mode, it will lock up the torque converter and hold your current gear more aggressively than in normal D. This causes compression braking. Believe it or not, this is actually good for fuel efficiency since the torque converter is locked up so there's less loss through the converter.

In addition, if you are headed up or downhill, same scenario as I said will apply.