if you read through all the threads on this board you will probably come to the conclusion that the SL oils are all very good, much better than others, with performance within the category improving as you increase the quality of the base oil (Group I to II, II to II+, II+ to III, and III to group IV & V blends; and lower the quantity of the VI improvers. Thus, one of the biggest advantages to group IV/V synthetics is in it's almost total lack of ability to shear down, and it's better pumpability at low temps.