Roush
oil, in the 5W-30 viscosity, has the same ZDDP level as Mobil1 0.08% (800 PPM). It probably has the "starburst" at that viscosity. Almost all synthetics have higher ZDDP when you go to their higher viscosity oils - 15W-50, 20W-50. The trick is getting the higher ZDDP at the lighter weights.
Bob