why major fuel consumtion on 1992 Nissan Pickup (D21)

im getting 10 mile a gallon

Asked by for the 1992 Nissan Pickup (D21)
2 answers
4cyl? 6cyl? Running ok? Worse mpg all of a sudden? Little more info!!
do you have a ck eng light on? if so ck codes and post so we can adv