Wrong oil?

[stangguy]

I recently bought a 1998 Mustang with the 3.8 v/6 engine. When I changed the oil, I put in 10w30 Delo, which is a diesel oil from a couple years ago that has higher levels of ZDDP. It just dawned on me that cars with catalytic converters shouldn't use high ZDDP oils. Does this engine even have flat tappets? It doesn't burn oil, so will the high ZDDP even be a problem for the cats? The car only has 79000 miles on it.

 

[slo town]

If it doesn't burn oil your cats will be fine on the Delo. Oil burners will kill cats even if you're using the correct oil.

Scott

 

[jagdriver727]

That engine has a roller valvetrain, you don’t need to be worried about ZDDP.

If it’s not burning oil, you won’t have an issue with the cats, so run it for the full OCI and change to a current-spec PCMO next time.

 

[Jimmy_Russells]

If it was Delo 400 XLE, it is SN rated.

 

[blufeb95]

If it was Delo 400 XLE, it is SN rated.

Sounds like what he was describing is that he used older oil that was CJ-4/SM rated which had closer to 1200ppm of phosphorus if I recall right, I don't think the Delo line up was reformulated for SN until around 2017.

 

[Chris142]

That car grew up on oil with higher zddp.

 

[RDY4WAR]

It will not harm anything unless you're consuming a lot of oil. Use it with confidence.