GTX High Mileage question

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Was grocery shopping at Walmart today and I always browse the oils to see if they have any new stuff. The new GTX High Mileage jugs/quarts (all weights) now say something to the effect of the phosphorus has been reduced to protect the catalyst and emissions system,and are using some advanced antiwear add in place of it. Is this a bad thing or are they using something that's better/more advanced? Does less phosphorus mean less zddp? Are all oils going toward this catalyst safe thing?
 
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Originally Posted By: aquariuscsm
Was grocery shopping at Walmart today and I always browse the oils to see if they have any new stuff. The new GTX High Mileage jugs/quarts (all weights) now say something to the effect of the phosphorus has been reduced to protect the catalyst and emissions system,and are using some advanced antiwear add in place of it. Is this a bad thing or are they using something that's better/more advanced? Does less phosphorus mean less zddp? Are all oils going toward this catalyst safe thing?
Phosphorous levels went down with the advent of SM and SN specs. This was done to protect catalysts as there was some concern that lighter weight oils were encouraging more oil consumption and thus more potential for cat damage. I don't know the Castrol story in particular, but some HM oils (Mobil1, Defy) are SL-rated because higher levels of phosphorous were retained. Other HM oils, like MaxLife, are SN-rated. SM/SN oils do a fine job of protecting engines based on everything we've seen here, so if Castrol has made the change from SL to SN, I wouldn't worry about it a bit. In fact, if my car consumed oil I'd probably feel even better about it.
 
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Maybe this reflects their fairly recent change to the "Resource Conserving" on the label. Yes it would mean less ZDDP, but that has certainly been the trend anyway.
 
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Saw the new bottles today at Dollar General. I wonder if they will change their spec sheet too? The previous Castrol HM was unusually thick for grade wonder if they stuck with that notion. I don't personally think lower ZDDP helps cats at all if you don't burn oil, but that is their marketing claim on the bottle.
 
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