Originally Posted By: ChrisGuerrero
Hi @dlundblad, our apologies for the delay in response! Some Shell Rotella products were previously API Sx rated to claim gasoline engine spec for HDDEO through the waiver process covering the use of high phosphorus content oil on dual-rated engines. However, upon the introduction of the newer generation API CK-4 & FA-4, this waiver was eliminated and stricter upper limits for phosphorus content took effect for the API Sx ratings (API SN, for example, requires Phosphorus content div>
Is the phosphorus limit just for hdeo oils? Mobil 1 lists phos. 1000 for the 0w-40 and 5w-50, 1200 for the 15w-50, all are sn