|SU.S. refinery light product yields have
increased since 1990, even as the quality of crude oils being run in
refineries has been declining.
|SBut yields for gasoline and distillate have
changed differently. Distillate yields
increased more than gasoline, rising about 3.5% since 1990.
|SGasoline yield from crude oil input has
changed very little, but it is up about 2% due to the addition of oxygenates
from outside the refinery.