We have learned over the last couple of years that there is no zinc in the oil anymore.Reason being is that most all new motors are roller cam systems,The lack of zinc in oil on flat tappet cams will chip the edges of the lobes,get into the oil pump,and thoroughly destroy your new motor from top to bottom.Lucas break in oil is readily available,or Brad Penn Oil,Made in the old Kendall Factory,yes its still green.Both of these are known to work to avoid the problem