Originally Posted By: rkpatt
I just changed the oil in a high mileage vehicle that had some minor seal leaks and oil consuptions issues using Quaker State Defy. After doing this, I happened read some articles that the ZDDP (zinc) additive from the exhaust of an oil burning engine can contaminates catalytic converters (leading to quicker failure ). As the car is somewhat of a slight oil burner, I will be drain out the QS Defy very soon and either go back with another HM or conventitional oil that doesn't push ZDDP .
IMHO, leave in the DEFY for a complete OCI and let it run it's course. The extra Zinc in the DEFY won't be the cause of your converter failure(if it fails at all). Converter failure will be caused from the years of "Blow By" that you've been experiencing, that may(MAY) cause your converter failure...again, if the converter even fails at all. Not from one oil change with an oil that only has some(SOME) extra Zinc!
If you've been expreiencing many years of Blow by, the DEFY only may be the final straw but, you'd be feeling some power deficiencies by now, from all of your past OCI's and the Blow By!
I really think that you'll like the DEFY
DEFY only has some extra Zinc that the(not long ago) SL/GF-3 oils had! About ~1000ppm then, as compared to the ~800ppm today!
Originally Posted By: Char Baby
I am currently using DEFY 5w30 in my older Firebird FORMULA V8-4bbl. And it has made the engine the smoothes/quietest even compared to MaxLife or Castrol HM/Castrol Start-Up. A little too quiet for this particular car(lost some rumble) and not quite to my liking for this particular car(although, I don't hate it and I may stay with it).
But, I love the smooth/quiet in our other cars.
ATMOF, I am using QS oils(QSUD, QSGB, DEFY) in all of my cars right now and it certainly has made my engines as smooth/quiet as any of the best oils that I have tried. Or I should say...certain oils make engines quiet compared to others and QS oil is one of them!
This '80 Firebird that I speak of, still has the original Catalytic Converter on it and it's had "Blow By" for years(when Zinc was really high) until I started using HM oils recently(DEFY today)
I just changed the oil in a high mileage vehicle that had some minor seal leaks and oil consuptions issues using Quaker State Defy. After doing this, I happened read some articles that the ZDDP (zinc) additive from the exhaust of an oil burning engine can contaminates catalytic converters (leading to quicker failure ). As the car is somewhat of a slight oil burner, I will be drain out the QS Defy very soon and either go back with another HM or conventitional oil that doesn't push ZDDP .
IMHO, leave in the DEFY for a complete OCI and let it run it's course. The extra Zinc in the DEFY won't be the cause of your converter failure(if it fails at all). Converter failure will be caused from the years of "Blow By" that you've been experiencing, that may(MAY) cause your converter failure...again, if the converter even fails at all. Not from one oil change with an oil that only has some(SOME) extra Zinc!
If you've been expreiencing many years of Blow by, the DEFY only may be the final straw but, you'd be feeling some power deficiencies by now, from all of your past OCI's and the Blow By!
I really think that you'll like the DEFY
DEFY only has some extra Zinc that the(not long ago) SL/GF-3 oils had! About ~1000ppm then, as compared to the ~800ppm today!
Originally Posted By: Char Baby
I am currently using DEFY 5w30 in my older Firebird FORMULA V8-4bbl. And it has made the engine the smoothes/quietest even compared to MaxLife or Castrol HM/Castrol Start-Up. A little too quiet for this particular car(lost some rumble) and not quite to my liking for this particular car(although, I don't hate it and I may stay with it).
But, I love the smooth/quiet in our other cars.
ATMOF, I am using QS oils(QSUD, QSGB, DEFY) in all of my cars right now and it certainly has made my engines as smooth/quiet as any of the best oils that I have tried. Or I should say...certain oils make engines quiet compared to others and QS oil is one of them!
This '80 Firebird that I speak of, still has the original Catalytic Converter on it and it's had "Blow By" for years(when Zinc was really high) until I started using HM oils recently(DEFY today)
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