It may have been covered but I don't remember seeing it. With the old SDF filters you changed the filters after 12500 miles or 6 months and the top up oil was supposed to boost up the additive package in the oil. Now the new Ea filters can be used for one year or 25000 miles. So is the top up boost not needed anymore? Could this be why the newer ASL and ATM oil is thinner than before.