Break in oils, zinc and all that jazz

jerry6 said
What does that mean , they broke down ?
and it's 10-40 not 15 - 40
http://www.royalpurpleconsumer.com/wp-content/uploads/PS_HPS_Motor_OIl.pdf

ive seen 4 engines spin rod bearings after switching to royal purple, same weight before and after the switch. Friends 2005 GT mustang spun one siting in my driveway as his apt wouldn't let him change the oil there.