[landspeed]

In terms of autos... my 1989 auto actually does care about the TC. When slowing down, it does fuel cut above 80km/h, but once the torque convertor lockup deactivates, it instantly starts using the same amount of fuel per engine cycle as it would at idle - which means it is better to put the transmission into neutral - so at least it 'idles' more slowly.

I've tried doing manual engine-cut using the keys (in gear) once or twice; after a few seconds, when you switch back to 'engine-on' mode, the engine seems to be turning at about 500rpm. I think it is quite bad for the transmission to be honest (which is why, if you have to tow an auto, it must not be in 'drive').