CVar cameraDistanceSmoothSpeed

Changes speed at which you scroll-wheel zoom in/out.

Default setting

 * 8.33

Possible settings

 * 0.002778 - 50

Changing this setting
In-game, type the following /console cameraDistanceSmoothSpeed setting

Alternatively, you can exit wow, open the Config-cache.wtf file, and add the following line: SET cameraDistanceSmoothSpeed setting