I saw a YouTube video today where real life pilots were trying to determine if drifting was faster than normal cornering or not. They tested it on 90° turns, 180° turns and a small race track on which they could measure lap time. The conclusion is that drifting is not faster, and sometimes slower, even with a professional pilot. Do you think it is the same in BeamNG? (I can give you the link to the video if you wish)
Personally it feels to me like drifting may be faster around specific tight corners, however the corner exit speed is sacrificed alot when drifting. So i think you can probably go around corners faster through drifting, but then doing a lap time would be quicker without drifting if that makes sense.