Stumbled on this last night and i found it interesting enough to do some research. Seems it is fine to use if the engine is not using oil. What do you think?
ZDDP and cats.
- Thread starter SpareParts
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Marky Dissod
Full Access Member
What do 'I' 'think'? Reality is what's left after you die.
So long as an engine does not burn oil, ZDDP stays in the oil and away from the catalytic converter, Bob's yer uncle.
Once an engine starts burning oil, zinc in the exhaust will eventually kill the catalytic converter.
It has since been proven that zinc is not necessarily required for well-beyond-adequate engine protection.
Also, take very seriously what Lake Speed Jr says, it'll save you a lot of money in the long run.
In another video he very strongly implied that a brand new vehicle's break-in oil change schedule should be far more often than typically suggested by OE.
I'm very strongly inclined to agree with him.
OP
OP
Im no expert on the subject at all.
I always took what i heard as fact but after seeing that vid it makes sense. ZDDP can't damage the cats if it is not getting to them.
I might experiment and put some in my Yukon using something like Royal Purple HPS oil the next oil change.
I always took what i heard as fact but after seeing that vid it makes sense. ZDDP can't damage the cats if it is not getting to them.
I might experiment and put some in my Yukon using something like Royal Purple HPS oil the next oil change.
yep, old flat tappet needed it, today's not so much.
as for cats, everything hurts them lol. Just depends on if it matters to you. if you live in California, where you can't eazily replace them. then I definitely wouldn't. if you live some place else and looking for a reason to remove them. then.all good.
as for cats, everything hurts them lol. Just depends on if it matters to you. if you live in California, where you can't eazily replace them. then I definitely wouldn't. if you live some place else and looking for a reason to remove them. then.all good.
OP
OP
Cats are not a big deal around here. Pretty sure 1/3rd of the vehicles around here don't have em.
Most run red diesel on road also.
Replacing with used would be pretty easy and cheap anyway
Most run red diesel on road also.
Replacing with used would be pretty easy and cheap anyway
strutaeng
Full Access Member
I ran Driven break in oil on my DIY engine rebuild, which I believe has ZDDP(?) Replaced around 600 miles. That's it.
I wouldn't run it regularly for reasons already stated.
My friend from church recently was telling me his 05 Tacoma needed all 4 catalytic converters. He went to the dealership and they quoted him $4600. Truck is not even worth that. The previous owner painted it, grill and all, and it's peeling all over the place.
I was still puzzled why it needed all catalytic converters, so I asked him a few questions, and it turns out it's burning oil. I was thinking maybe he had a misfire, but burning oil makes perfect sense.
I told him about Rockauto.com and at least the cats are cheaper there. Not sure what he's gonna do? It's his work truck as a handyman.
I wouldn't run it regularly for reasons already stated.
My friend from church recently was telling me his 05 Tacoma needed all 4 catalytic converters. He went to the dealership and they quoted him $4600. Truck is not even worth that. The previous owner painted it, grill and all, and it's peeling all over the place.
I was still puzzled why it needed all catalytic converters, so I asked him a few questions, and it turns out it's burning oil. I was thinking maybe he had a misfire, but burning oil makes perfect sense.
I told him about Rockauto.com and at least the cats are cheaper there. Not sure what he's gonna do? It's his work truck as a handyman.
OP
OP
If i needed a cat i would buy used or delete. I do know where i can get 2 used sets Monday if i needed + they are several Yukon's being parted out on marketplace.
Driven break in oil is about 2800ppm.
Driven break in oil is about 2800ppm.
strutaeng
Full Access Member
Just curious: What makes you think you need to run ZDDP?
I remember saying zinc was removed from the regular oils back innthe early 2000s because the auto manufacturers started requiring catalytic converters for over 100k.
So I think running it is fine, but over long term, engine will start burning "some" oil, and that's when your cats will be damaged. Just like in my previous example from my friend and his Tacoma.
Also, aren't those oils actually more expensive? I'm not any kind of oil expert, but thought only break-in oils had zinc, and maybe the specialty oil for the older guys running the flat tappet stuff? IDK I think 6 qts. of Driven was like $65 a few years ago.
I'd never heard of zinc in oil until I started watching LSJr
OP
OP
From what i read our current oils have 800ppm max but could be less. European oils have more i think.
Zinc does more than just help keep a flat tappet alive. Too much causes wear. I have read in a few places that 1200ppm is good in a proper running engine.
Break in oils have higher zinc to help promote engine parts mating for break in and that is why you only want it for no more than 500 miles.
Zinc also reduces friction of every moving part. 1200ppm is about the perfect amount. Government mandates the amount of zinc an oil can have not engine producers/automakers.
That's all i have read and probably not digging into it further.
Zinc does more than just help keep a flat tappet alive. Too much causes wear. I have read in a few places that 1200ppm is good in a proper running engine.
Break in oils have higher zinc to help promote engine parts mating for break in and that is why you only want it for no more than 500 miles.
Zinc also reduces friction of every moving part. 1200ppm is about the perfect amount. Government mandates the amount of zinc an oil can have not engine producers/automakers.
That's all i have read and probably not digging into it further.
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