NAPA Syn 15W-50 3.49/quart
#31
Banned
iTrader: (9)
Diesel oils zinc & phos levels have come way down also. Any motor oil SN has only 800 ppm of Zinc & phos inwhich is very low for any marine app. That is correct about ZDDP will kill at catalyst over time hence for the reduce levels.
Oil groups - group III is really not a syn oil, its more like a hydro cracked oil, Group IV oil based is a PAO and group V is ester based. Driven oil (ex joe Gibbs oil) is a MPAO inwhich is claimed to be a very good oil. Lake Speed Jr. heads up that program.
Mercruiser new recommended 20w -40 syn oil for their catalyst motors also has reduce levels of ZDDP compared to their orignal 25 w 40. In the marine world there is alot of things that will ruin the catalyst.
Run the boat out of gas and you will burn a hole straight thru the catalyst sub strake also certain gasket adhesives will hurt them, also backfires can burn a hole thru them, worn spark plugs over time will the hurt the catalyst and any water reversion will kill the cat on the spot among other things. FYI.
Oil groups - group III is really not a syn oil, its more like a hydro cracked oil, Group IV oil based is a PAO and group V is ester based. Driven oil (ex joe Gibbs oil) is a MPAO inwhich is claimed to be a very good oil. Lake Speed Jr. heads up that program.
Mercruiser new recommended 20w -40 syn oil for their catalyst motors also has reduce levels of ZDDP compared to their orignal 25 w 40. In the marine world there is alot of things that will ruin the catalyst.
Run the boat out of gas and you will burn a hole straight thru the catalyst sub strake also certain gasket adhesives will hurt them, also backfires can burn a hole thru them, worn spark plugs over time will the hurt the catalyst and any water reversion will kill the cat on the spot among other things. FYI.
Last edited by BUP; 04-13-2013 at 01:18 AM.