Javaknight

Has anyone noticed that the car almost seems to go into neutral for a sec when downshifting with S-tronic? I have an 2001 A6 2.7T and when I downshift it immediately begins braking the car which is what I expect. The first time I downshifted in the A5 it felt like the car was just rolling free and freaked me out.

Just a weird quirk of the car or just my imagination?

superswiss

Well, it does go into neutral for a brief moment so to speak. The S-tronic is mechanically two manual transmissions. In order to downshift it declutches both transmissions in order to rev match the engine. During that brief moment, the drivetrain is completely decoupled from the engine and hence the car is rolling free. It's the same thing as with a manual transmission. You push the clutch in and the car rolls free until you let the clutch back out. A traditional automatic transmission never decouples. There is always fluid coupling between the engine and the drivetrain via the torque converter.

JohnEnglish

Also, if you downshift unexpectedly yeah the transmission will "hang" for a second as it shift out of the anticipated gear it was in to complete the downshift.

Javaknight

makes sense. Only noticed it because the transition between gears is so much quicker with the A6.