Oill least likely to damage catalytic converters?

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All,

My car burns oil either by the way of valve stem seals or rings.

I'd like to know how to identify which oils are least likely to damage my cats if there is such a measurable with respect to ingredients.

The purpose of this post is not to address how to fix the oil issue, that has been addressed in another thread.

My intention is to continue to use high mileage oils.

Thanks.
 
As Broc said, low SAPS oils are least damaging for catcons. That's directly opposite to your statment that you intend to use high mileage oils, as *most* of those are full-SAPS oils as appropriate for older vehicles.
 
I could be wrong, but recently read somewhere that "Mobil 1 0w30 ESP" is the least damaging. But in that discussion there was a direct comparison between "M1 0w30 AFE" and "M1 0w30 ESP", and ESP came out on top as far as reduction in damage for catalytic converter.
 
Would be nice to know which one, because a high mileage oil won't help much to help if its rings. Have someone start your car in the morning cold and watch the tailpipe. Check for a puff of blue smoke. If you see that, its likely the rubber valve seals which can benefit from a high mileage oil. Worst case if you throw a P0420 theres always the $6 spark plug non fouler exhaust mod.
 
How much oil burning are you talking? Clearly with the reports of new cars using a quart in 1200 miles and still being acceptable shows that it takes more consumption than that to inactivate a catalyst.
 
Originally Posted By: BrocLuno
Low phosphorus oils. Get as low a Phos count as you can.


Thanks.
 
Originally Posted By: 440Magnum
As Broc said, low SAPS oils are least damaging for catcons. That's directly opposite to your statment that you intend to use high mileage oils, as *most* of those are full-SAPS oils as appropriate for older vehicles.


Very helpful.
 
Originally Posted By: Vlad_the_Russian
I could be wrong, but recently read somewhere that "Mobil 1 0w30 ESP" is the least damaging. But in that discussion there was a direct comparison between "M1 0w30 AFE" and "M1 0w30 ESP", and ESP came out on top as far as reduction in damage for catalytic converter.


Thanks, helpful.
 
A low ash (Low Zinc & Phosphorus) oil that is one SAE group up from OEM would work. In Acea terms that would mean a C2 or C3, BUT I would add half a can of Liqui Moly Ceratec (Contains Moly and a hexagonal form of Boron Nitride) to help offset the lack of AW add's in DPF approved oils.

It would also be worth trying an HM oil or half a can of LM Motor protect. Mobil and Valvoline both make good HM oils, although not many are low ash.
 
Originally Posted By: LeakySeals
Would be nice to know which one, because a high mileage oil won't help much to help if its rings. Have someone start your car in the morning cold and watch the tailpipe. Check for a puff of blue smoke. If you see that, its likely the rubber valve seals which can benefit from a high mileage oil. Worst case if you throw a P0420 theres always the $6 spark plug non fouler exhaust mod.


I usually go with that theory (the puff....well plume) of smoke only on startup that goes away), but I figure it is rings since the valve seals really aren't that exposed to oil due to gravity. So HM doesn't do much for rings eh? I never thought about the trick you mentioned...very valid.

Good to know.
 
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Originally Posted By: kschachn
How much oil burning are you talking? Clearly with the reports of new cars using a quart in 1200 miles and still being acceptable shows that it takes more consumption than that to inactivate a catalyst.


Good question. 1 quart every 700-800 miles. I just got the hunk of junk that was once someone elses problem but is now mine.
 
Originally Posted By: aquariuscsm
GTX High Mileage advertises on the label to be low phos and cat friendly.


Thanks!
 
Originally Posted By: dx92beater
Originally Posted By: LeakySeals
Would be nice to know which one, because a high mileage oil won't help much to help if its rings. Have someone start your car in the morning cold and watch the tailpipe. Check for a puff of blue smoke. If you see that, its likely the rubber valve seals which can benefit from a high mileage oil. Worst case if you throw a P0420 theres always the $6 spark plug non fouler exhaust mod.


I usually go with that theory (the puff....well plume) of smoke only on startup that goes away), but I figure it is rings since the valve seals really aren't that exposed to oil due to gravity. So HM doesn't do much for rings eh?

Good to know.


High mileage oils advertise "more cleaning". Wouldn't this help clean the rings if that's what is causing oil burn?
 
Originally Posted By: edyvw
Of all oils available here Mobil1 5W30 ESP has least amount of SAPS. Sometimes NAPA has that oil on sale for $5.99


Thanks.
 
Originally Posted By: UltrafanUK
A low ash (Low Zinc & Phosphorus) oil that is one SAE group up from OEM would work. In Acea terms that would mean a C2 or C3, BUT I would add half a can of Liqui Moly Ceratec (Contains Moly and a hexagonal form of Boron Nitride) to help offset the lack of AW add's in DPF approved oils.

It would also be worth trying an HM oil or half a can of LM Motor protect. Mobil and Valvoline both make good HM oils, although not many are low ash.


Thanks.
 
Originally Posted By: aquariuscsm
Originally Posted By: dx92beater
Originally Posted By: LeakySeals
Would be nice to know which one, because a high mileage oil won't help much to help if its rings. Have someone start your car in the morning cold and watch the tailpipe. Check for a puff of blue smoke. If you see that, its likely the rubber valve seals which can benefit from a high mileage oil. Worst case if you throw a P0420 theres always the $6 spark plug non fouler exhaust mod.


I usually go with that theory (the puff....well plume) of smoke only on startup that goes away), but I figure it is rings since the valve seals really aren't that exposed to oil due to gravity. So HM doesn't do much for rings eh?

Good to know.


High mileage oils advertise "more cleaning". Wouldn't this help clean the rings if that's what is causing oil burn?


Also, not as easy to identify which one. It's a boxer motor. A compression test that used to take me 15 minutes to do perfectly now takes 4 hours. Ditto to the leakdown test. I don't have my tools near me either.

I can tell you that I put a piece of paper over the oil cap with it running and no movement. I can tell you that I removed the PCV hose and that it did not appear to be blocked....but there was oil sitting on top of the PCV which might make sense since it sits vertically....and yes I swapped the PCV valve out already with an OEM one.
 
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I wish I didn't entitle the thread oil lol....but maybe the extra "l" is synonymous with all of the "oilllll" I am burning.
 
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