Originally Posted By: rangerfan24
Are the old green cap and blue cap and red cap mobil 1s better formulated than todays?Thanx
After the resolution of Mobil's complaints against Castrol and the merger of Exxon and Mobil, both of which occurred in 1999, data available from product data sheets (pds) would indicate that E/M Corporation, at the latest, began blending Group III base oils into many of their formulas sold in the US beginning with the SL period (2001). If you can't beat 'em, join 'em.
However, from the numbers listed on pds, the base oil for the SM 5W30 do appear better than those for the SL 5W30. In addition, the SM formula is slightly more viscous, which some may find more desirable.
Will it make a difference for most (almost all) applications? Nope.