Listers
The mechanic is right. According to my sources is the current SL service
rating "Energy Conserving' SL oils have a phosphorus limit not applied
to earlier service ratings. This is done to extend catalytic converter life.
The source of the phosphorus is the ZDP anti-scuff additive used to
protect engine parts from wear, especially camshafts. With newer
engines with overhead camshafts that have low spring pressures
or with roller tappets, this should not be an issue. With heavy duty
springs and/or high lift camshafts, this is an issue. Anti-scuff
additives are necessary. Any oil rated CI-4 and intended for
diesels hall all the necessary additives. Shell Rotella has always
been among the best. It pays to read the service ratings.
I'm not sure where Moboil 1 stands with this.
Dave
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