Dropping gear to reduce drag

Interference drag is generated by the mixing of airflow streamlines between airframe components. For example, between the landing gear strut and the fuselage. As air flows around different aircraft components and mixes, a localized shock wave is formed, creating a drag sum greater than the drag that components would have by themselves.

You have to be mindful though of restrictions in regards to the speed at which you’re flying. There would be no adverse effects on the gear because of your speed but in the real world there are limits.

Trying sticking your hand out the window. When your hand is horizontal like an airfoil, it’s easy to stick outside the window. But when you open your hand into the wind, your hand flies backwards, and requires a lot more force to hold it position.

Dropping the landing gear produces a large amount of form drag. Form drag is the result of an object’s general shape in relation to the relative wind.

Reference: CBoldMethod