Kanina pa ako nag google about rear wings and spoilers ang sabi they improve the drag coefficient, kung ganun can they also improve the car's mileage, tama ba?

if I install one on my stock car that frequently runs 90-100 kph on the windy star tollway going to and from batangas gumanda kaya mileage ng tsikot ko, I know they are useless in traffic


sa mga expert po please enlighten me, thanks in advance