blueskis In my experience, not only does use & effects of carb heat vary with different makes of engine, it varies with all the Lycomings in different types, in the types that I fly.
On the PA28-181 & PA28R-201(Wot Rubbish!! its fuel injected), I select carb heat on base leg & back to cold on finals, at about 200/300 ft.
The AA5B/AG5Bs seem to hate carb heat, & sound very huffy (or whatever the techie term is!) after more than a few minutes on hot, so I usually select cold before 400 ft.
The GA7s very, very rarely seem to get carb icing, & I was taught not to select carb icing on base/final at all. But, as with most twins, you tend to keep more power on base & finals, than with some singles.
Flap settings for T & Gs on grass:-
It is interesting the number of different techniques that have now been aired on this thread.
I have never tried a T & G on grass, (or on short tarmac runways)leaving more than 1/3 on the PA28s, or nil on those with the electric flaps. Except, of course, occasionally when training, when I forgot to retract any flap at all!
I am still chewing over the relative merits of flap settings for grass, in terms of lift & airspeed, v drag. I was taught that the aim was to get the aircraft airbourne in as short as possible run, then hold it in ground effect to build up speed.
I don't do really short grass runways (<500m) 'cos they are much too scary.
For those of you who do use short grass runways, what flap setting & other techniques do YOU use?
Or, I suppose you never do T & Gs, 'cos you do perfect landings at every first attempt!
(Edited for brain failure, before someone else spots it
)