I sent in two samples (one new and one used) of Valvoline VR1 20w-50 racing oil for analysis at the local Caterpillar oil lab. This is thier SM rated oil, part number 211 that they claim has extra zinc. Results for the new oil sample in ppm Al-0 Ca-2121 Cr-0 Cu-0 Fe-1 Pb-0 Mg-21 Mo-0 P-1049 K-5 Si-4 Ag-1 Na-0 Sn-0 Zn-1182 The used oil sample had Zn-1172