not true shell t1 has a min of 1400 ppm of zinc the shell rotella t4 t5 t6 . is reduced zinc for the newer low emission engines .that's what I was told by a shell rep 2 days ago .
So that is why Rotella T1 does not meet the newer CK-4 designation. Good to know. Now, too bad it only comes in "straight" weights; SAE10, SAE30, SAE40.
