From Wikipedia:

> A semi-automatic transmission ... is an automobile transmission that does not change gears automatically, but rather facilitates manual gear changes by dispensing with the need to press a clutch pedal at the same time as changing gears.

I wasn't talking about clutch-and-stick vs. push-a-button. I was talking about controlling which gear is on vs. letting the car guess alone. I've never heard about race cars where the driver does not decide himself which gear is on at which moment; if you have, thanks for letting me learn something new.

I don't know of a lot of F1/automatic gear cars being involved in steep terrain where the engine braking scenario would come into its own.

The grandpartent comment clearly says "or running a car race" as another example.

That said, I see no reason why a (semi-)automatic couldn't engine brake.

> I see no reason why a (semi-)automatic couldn't engine brake.

The semi surely can. The full automatic, I don't know. How can the car understand that you want a lower gear before you touch the brake?

I understand, my point was that manual shift cars are used in every discipline where such things matter like rally driving afaik

You mean like WRC?

Better update yourself.

The Subaru Impreza WRC2004 gearbox does a gear change in 0.05s vs 1s taken by the best manual ones.

http://m.crash.net/wrc/feature/112516/1/technical-talk-semia...

Do you know any WRC driver able to beat that?