Answer: slipstreaming

AnswerCrossword Clue
SLIPSTREAMINGReducing air resistance
slipstreaming(esp. in auto racing)Another term for draft (sense 4 of the verb)
slipstreamingSLIPSTREAM, to drive in the slipstream of a vehicle
slipstreamingTravel in the slipstream of (someone), esp. in order to overtake them