Rotella has the DPF (diesel particulate filter) compliant additive package, which means the ZDDP level is reduced from the original level. Also, the current CJ-4 API rating on Rotella T mandates a higher level of dispersant additives, and these dispersant additives compete against the formation of the ZDDP anti-wear film. In slower speed diesel engines, this is not a problem. However, it is an issue in higher speed, flat tappet, gasoline engines.