Planning descents

[thinwing]

I dont think carb heat use increases an engines efficiency at all...you are correct that it causes a richer mixture with the hotter,less dense air supplied to carburator causing at least an in drop in manufold pressure.I really tested this with a full throttle takeoff with carb heat left on from a 4500 lake in B.C.That power loss meant that I could not get an amphib Husky on the step(carb lycoming 0360)at full throttle...soon as carb heat was removed ,it was another in and a half manu. pressure and up we went.I dont call that efficiency,just another trade off while deicing a ice choked carb...kpc

[Mooneymite]

Quote: thinwing

I dont think carb heat use increases an engines efficiency at all...you are correct that it causes a richer mixture with the hotter,less dense air supplied to carburator causing at least an in drop in manufold pressure.I really tested this with a full throttle takeoff with carb heat left on from a 4500 lake in B.C.That power loss meant that I could not get an amphib Husky on the step(carb lycoming 0360)at full throttle...soon as carb heat was removed ,it was another in and a half manu. pressure and up we went.I dont call that efficiency,just another trade off while deicing a ice choked carb...kpc