Sulfated Ash, High and Low, which is better?

[dole]

Could anyone enlighten me. Thanks.

I saw Mobil 1 0W-40 with 1.2% of Sulfated Ash, whereas, EP and 5W-30 only 0.8%.
Pros and Cons? why 40 is high on ash?

Thanks again.

 

[FCD]

A SN 5W-30 is limited at 800ppm of phosphorous, this does not apply to 40,50 or 60 grades so 0W-40 can have 1200ppm ( there is no limit ).
Higher SAPS in theory is worse for catalytic converters, but i have never heard of a catalytic converter being clogged by using a high SAPS oil.

 

[ragtoplvr]

I clogged my cat. Of course I was burning a quart every 400 to 5000 miles. Took about 30K of this.

91 Dakota 2.5 4Cy with 5 speed theft deterrent device.

The engine has high blowby. PVC is clean and new hose. Still huffs out the oil fill cap and dumping some oil in the air cleaner housing.

Oil turns black within 1000 miles. Looks diesel black.

Yet does not foul plugs.

It won't die, and runs just fine, get 22 to 24 all the time. Except then the cat plugged.

Rod

 

[Olas]

The API impose limits based on KV. Depending on what you want, high saps protects engine whereas low saps protects cats.
Which would you rather replace?

 

[MolaKule]

https://www.astm.org/Standards/D874.htm

 

[dole]

thank you all for kind reply.

But I learn by searching that, SAPS tests will burn the oil and see how much residuals remain. This smells like bad oxidation pollutants left on engine, bad, isn't it? just hunch feeling.

 

[FCD]

It shouldn't be a problem if the engine does not burn oil.

 

[dole]

good logic. thanks.