I see that the phosphorus (antiwear component of ZDDP) level was only 825 ppm in your sample of Delo 15W-40 and that it had the low end of viscosity (12.6 cSt @ 100°C). The viscosity range for 40-grade oils is 12.5 to <16.3 cSt.
That was what was in it when I bought it. It has been switched back to Rotella T4 15/40.
The last analysis report for T4 I saw on Bob is the Oilguy showed similar Zinc levels and Phos around 900-1000 ppm IIRC. I don't recall the viscosity but there were no negative comments on it so I assume it is acceptable.
Kevin
