The big downside of full-time 4WD and AWD is that they use much more fuel than part-time 4WD because the engine has to transfer power to all four wheels, all the time.
Upande mwingine mkubwa wa muda 4WD na AWD ni kwamba wanatumia mafuta mengi zaidi kuliko sehemu ya muda 4WD kwa sababu injini ina kuhamisha mamlaka ya magurudumu zote nne, wakati wote.