FC improvement with no aircon usage

[IceBerG71]

just to check on cool days and night, opening the windows does it really help to improve ur FC? some of my friends say it might as aircon contrivute a high amount of petrol but winding down the windows break the streamline of the car as air now travels into the car. this also contribute to air drag and hence will affect FC.

is this true? which shall i believe in?

[WIl_ron]

just to check on cool days and night, opening the windows does it really help to improve ur FC? some of my friends say it might as aircon contrivute a high amount of petrol but winding down the windows break the streamline of the car as air now travels into the car. this also contribute to air drag and hence will affect FC.

is this true? which shall i believe in?

off air con save petrol is true
open window as long as speed not greater than 80 shld not cause u much drag

[Alvinyzw]

It's the same 1 lo, but open aircon waste more fuel so better still wind down windows.