No, not necessarily. The 0.08% max Phosphorus limit in SM only applies to the so-called ILSAC grades (0W20, 0W30, 5W20, 5W30 & 10W30). In 15W40s (the commonest HDDO grade), you can put in as much ZDDP as you like as long as it equates to being greater than 0.06% Phos. I seem to recall as well that the way the rules are written, even if you have say a 10W30 HDDO, as long as you state the diesel spec first (eg CH-4, CI-4, etc), then the following SM claim does not have to comply with the 0.08% max Phos spec.