Answer: lowgear

AnswerCrossword Clue
LOWGEARIt helps when climbing hills
LOWGEARShifting choice for a hill
LOWGEARTransmission choice for going uphill
LOWGEARAid in driving uphill
LOWGEARFirst
LOWGEARFirst, e.g.
LOWGEARIt's good for climbing hills
LOWGEARA truck may go uphill in it
LOWGEAR1, to a trucker
LOWGEARFirst, in terms of transmission