Only the Valvoline oils designated as "RACING" contain ZDDP. This was a 'pollutant' that the EPA mandated removal from commerce, but not from racing, hence the RACING label
That is incorrect/ ALL Valvoline oil has ZDDP in it, with the standard Valvoline having .08 PPM (same as what was used when these trucks were new, BTW). The have a propriatory ZDDP blend that keeps the phosphorus (which is not only the anti-wear agent, but is also what fouls catalytic converters) from burning off. The VR-1 and Rousch oils Valvoline produces have a higher ZDDP level, around .10-.12 PPM.
