Though it will not harm your transmission to shift into Neutral while your vehicle is in motion, the additional wear on your brakes by leaving the transmission in Drive will be negligible over the life of the brake pads. It is that minor. NEVER, EVER go into neutral while slowing down to a stop, for 3 reasons: 1. https://mechanics.stackexchange.com/questions/3902/automatic-transmission-is-shifting-to-neutral-while-approaching-stops-bad
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Though it will not harm your transmission to shift into Neutral while your vehicle is in motion, the additional wear on your brakes by leaving the transmission in Drive will be negligible over the life of the brake pads. It is that minor. NEVER, EVER go into neutral while slowing down to a stop, for 3 reasons: 1.
https://mechanics.stackexchange.com/questions/3902/automatic-transmission-is-shifting-to-neutral-while-approaching-stops-bad