[serialk11r]

Depends on the transmission. Basically all automatics these days have a lockup clutch on the torque converter to avoid said losses as often as possible. They can be programmed to provide engine braking by locking up under deceleration, and I'd guess that there would be a fuel cutoff function too. I think all Hondas will engine brake to some extent.

This is a big reason why automatics are starting to score higher on EPA tests. They typically run wider spaced gears with a much taller final gear, are programmed to lock the torque converter a lot, and are programmed to shift up early under light acceleration. This matters for the EPA test since most of the scoring is done on tests where acceleration is extremely leisurely, which is bad for engine efficiency. The automatic transmission can get around this by shifting up sooner and increasing engine load, whereas a manual transmission is not allowed to shift until some speed.

Automatics still need some amount of power to select gears by activating clutches, and provide hydraulic pressure for the torque converter, so a manual transmission in the right hands with around the same gearing will get better fuel economy.