What Oil Type To Protect Catalytic Converter?

[Nessism1]

Living in California, every few years we have to get a "smog test" to make sure our vehicles are not polluting excessively. A properly functioning catalytic converter is critical to passing these tests.

Simple answer: get an API SP oil? A lot of folks around here think API is weak sauce, though.

Low SAPS Euro oil? Would that be a better option? I've read here that Mobil 1 ESP 0W-30 has too much phosphorus to qualify for API SP, yet they tout protection of the CAT in their literature.

I'm confused...and most likely, overthinking.

 

[OneLonelyBurrito]

Heat is the typical mode of deactivating a catalytic converter. Oil can do it but isn’t the main reason. When testing catalytic converters, they are all aged with heat to there end of life condition. So your choice of oil most likely isn’t gonna matter unless you’re burning tons of oil.

 

[tcp71]

Anything with a Porsche C30, MB 229.31 or VW 504 00/507 00 specification should treat you right.

 

[Tifosi]

Living in California, every few years we have to get a "smog test" to make sure our vehicles are not polluting excessively. A properly functioning catalytic converter is critical to passing these tests.

Simple answer: get an API SP oil? A lot of folks around here think API is weak sauce, though.

Low SAPS Euro oil? Would that be a better option? I've read here that Mobil 1 ESP 0W-30 has too much phosphorus to qualify for API SP, yet they tout protection of the CAT in their literature.

I'm confused...and most likely, overthinking.

My recently purchased Mobil 1 ESP 0W-30 says API SQ

 

[Rand]

My recently purchased Mobil 1 ESP 0W-30 says API SQ

But, it isn't API SQ.

 

[slacktide_bitog]

Is it for the Civic in your sig, or for a different car?

For the Civic, Supertech Advanced Synthetic High Mileage 5w30 would be a fine choice.

 

[iCurious]

First what car is it?

 

[kschachn]

How much oil are you burning? If you’re not burning a lot or very little then it doesn’t matter. The oil has to get there first to be a problem.

The one time I saw a catalyst code due to oil burning was in a car that was consuming in excess of 1 quart over 500 miles and the guy was using an HDEO.

 

[thickvthin]

1999 f150 bought in California burns oil since day 1. 500 miles and I add 1 quart lol. mostly Mobil 1 synthetic. still original catalytic converter. all good. 200k+ miles. my own data could be an outlier. i don't have a definitive answer.

 

[RallyXaDSM]

My recently purchased Mobil 1 ESP 0W-30 says API SQ

It might meet the requirements and be "suitable" for applications that call for it, but it isn't API licensed

 

[cheesepuffs2]

Mobil 1 Extended Performance in my opinion gets overlooked here these days due to the understandable Mobil 1 ESP hype, but if you don’t want to run Mobil 1 ESP, Mobil 1 Extended Performance is still a great product that will serve you well.

 

[Nessism1]

Reason for the question is because I got caught behind a 10 year old car in traffic today, and the exhaust reeked. Clearly, the CAT was wasted on that thing. Then I started to wonder...

My car doesn't burn, and I've only used API oil up to this point. I'll try something Euro soon, though.

 

[Hohn]

Living in California, every few years we have to get a "smog test" to make sure our vehicles are not polluting excessively. A properly functioning catalytic converter is critical to passing these tests.

Simple answer: get an API SP oil? A lot of folks around here think API is weak sauce, though.

Low SAPS Euro oil? Would that be a better option? I've read here that Mobil 1 ESP 0W-30 has too much phosphorus to qualify for API SP, yet they tout protection of the CAT in their literature.

I'm confused...and most likely, overthinking.

Around here it’s quite common that we pick apart aspects of an oil blend without keeping in mind that it’s the total performance of the oil, not it’s recipe per se, that matters.

If you just look at additive levels, you’d conclude Pennzoil Ultra Platinum (that’s for you, mods) is a weak oil. But it’s a very good oil and there’s lots of evidence to back that up. But just a VOA would suggest it’s “weak sauce.”

I think the mid-SAPS Euro oils are a good sweet spot between preserving enough SAPS to be robust while all but eliminating catalyst risk in a healthy engine.

If you use premium bases, a low-SAPS oil can work very well, you just have to limit the OCIs.

 

[Tifosi]

But, it isn't API SQ.

 

[RallyXaDSM]

View attachment 323853

Meets or exceeds SQ engine test requirements ≠ formally approved and SQ licensed, which is why it's not listed in API's database. We know from the actual approvals listed below it that it's a much much better oil than what SQ requires anyway.

 

[kschachn]

Reason for the question is because I got caught behind a 10 year old car in traffic today, and the exhaust reeked. Clearly, the CAT was wasted on that thing. Then I started to wonder...

That’s a different problem than phosphorus poisoning.

 

[Arc]

Get the car up to operating temp and suck a quart of atf into it until it starts smoking so you know it soaked the cats. Shut it off and let it sit overnight. Start the car early before your neighbors get up because she is going to smoke a lot. Your cats will be like new and free of carbon buildup after about ten miles of hard driving. Yes Ive looked at cats before and after and it works. The atf will remove carbon buildup.

 

[SOUNDMAN5000]

I may be wrong in my thinking but being your car has a Cat, whatever spec oil your owners guide suggest would perhaps be the best all around oil for the car and would be Cat safe? I would stay away from anything labeled "RACING" as you don't want high levels of ZINC but I doubt I would give it any more thought than that?

I live in a State that no longer requires auto / motorcycle inspections ( did 20+ years ago) I was considering retiring one State over however that State requires inspections and is possibly the one reason I may stay in the State I am at. Once you get away from State "Silly" With all the Harley / motorcycles in the garage It would be a big PITA for me to deal with "regulations" again...

Nothing like a State Size HOA telling me what to do or not do...

 

[kschachn]

Get the car up to operating temp and suck a quart of atf into it until it starts smoking so you know it soaked the cats. Shut it off and let it sit overnight. Start the car early before your neighbors get up because she is going to smoke a lot. Your cats will be like new and free of carbon buildup after about ten miles of hard driving. Yes Ive looked at cats before and after and it works. The atf will remove carbon buildup.

The OP has a problem with carbon buildup?

 

[Kira]

Get the car up to operating temp and suck a quart of atf into it until it starts smoking so you know it soaked the cats.

How does one do that?
I've heard of trickling oil into the air intake.
I've also heard of using the brake booster's vacuum hose to let the engine suck it up like an elephant's trunk; which seems risky to me due to hydrolock.

Also, is there a preferred type of ATF to use (conv. vs. synthetic?)

Also, does this procedure require the whole quart?