[RedDevil]

Originally Posted by serialk11r

I think 3rd or higher is always a good idea if you can get enough speed, because when you're driving the engine with the wheels not only the mechanical advantage is reversed, but some types of gear meshes have lower efficiency being driven in reverse.

True, if speed allows you should always use fifth gear unless you have more gears in the box
But this even goes for push starts at near walking pace.
Once the engine turns over even slowly it probably gets enough juice to make the ignition work (make sure the lights, radio, window heater etc are all off).

Old diesels don't need much electrical power at all to tick over, like none. Just a sledge hammer to get moving.
3rd gear at walking pace may be too high to get enough revs to make a dead gasser fire, but diesels will go after the first passing of TDC.

My sea scouting club had a couple of boats with heavy hand cranked two cylinder diesel engines. In ten years the occasional kickback from starting those caused many injuries, amongst which at least one broken wrist.

Btw my wife can, and does, drive a manual. Like a cannibal on steroids. It never sees fifth gear. One reason for It's appaling FE.