Rotella doesn't make any synthetic oils.
Is this a reference to some of the manufacturers labelling semi synthetic as fully synthetics, due to some change in the definition of a synthetic? Not baiting, just curious.
Rotella 5w-40 synthetic
To my knowledge, Rotella does not (nor ever did) make a 15w/40 synthetic. They only made the 15w/40 dino oil. If you were running that in your ALH, start saving for a turbo.The 5W/40 T6 synthetic meets the 505.00 specs for VW rotary injection pump engines. It does not however meet the specs for the PD motors (or, has not been submitted for testing AFAIK).