Brad Penn 20/50 SEMI SYNTETIC VS. Free flow 300 cell Cat.

[david.avrahami@]

1987 Carrera...I have done some reading on the effect of ZDDP in Brad Penn 20/50 semi synthetic motor oil on its adverse effect on the life and effectiveness of a Catalytic converter.
I intend to replace my current Mobil 15/50 synthetic with the Brad penn alternative in order to provide engine friction protection BUT I am concerned about its effect on a top quality 300 cell Cat converter (free flow)
Can some Pelican actually uses this particular motor oil in combination with a free flow cat. that experienced deterioration of the Cat? and a smelly exhaust?

[KNS]

In my daily driver 2004 325i, I have been using Rotella T6 5W-40. T6 has high Zinc and Phos similar to Brad Penn. The car now has just under 200,000 miles on it and I've been using the T6 for about 100,000 miles. The cats on the 325 are tiny and it just passed emissions testing (yet again) a few months ago.

I believe the Mobil 15W-50 has nearly the same zinc and phos numbers as the Brad Pen (maybe slightly less). You shouldn't have any issues.

Your 300 cell cat is less restrictive than the factory cat and you should not have any funny smells.

[Rich Gas]

I'm using Brad Penn 20/50 with a 200 cell FabSpeed Sport Cat...no deteriorating, no unusual smells. Although, I had some weird coking issues, which could be attributed to my driving style...I think the previous owner babied the car too much, and built up internal deposits, which I broke loose.

[david.avrahami@]

rich gas...what do you mean by coking issues? can you describe?

[Rich Gas]

Generally pertains to turbo motors, but...

Carbon Granules in Oil Tank

[Quicksilver]

Yes: Using an oil high in ZDDP will degrade your catalytic converter until it will fail to pass smog.

An absolute fact.

Assuming there is nothing else contributing the the degradation (such as excessive oil consumption) you should expect the CAT to fail in 150K miles or so.

[david.avrahami@]

Thanks for your responses...Presently I have 86,000 miles on the car, oil consumption is normal and my intention is to change my existing 100 cell cat to a 300 cell high flow and superior quality cat. AND at the same time change M1 15/50 to Brad Penn 20/50.
I hope to still help the green planet provide a free flow exhaust for performance and protect the metal moving engine parts.
I hope I am not waisting money and time

[Marc Bixen]

Cats are cheaper than motors. Enough said!

[DanielDudley]

I have seen a few engines now with bad cams and followers. This is what the additives protect. No one has clearly demonstrated to me that there is any other oil formulation that will protect the engine as well.

A lot of things can happen in 150,000 miles, assuming you manage to drive your car that much. I'd be delighted if I could manage to put that many recreational miles in during the course of the next twenty years or so. I can't drive my fun cars to work, nor would I expose them to mundane commuter driving. And I do mean mundane. Of course Your Mileage May Vary.

If you put 2.00 in a piggy bank every time you fill up the car, you should easily have the costs covered by the time you need to replace the cat. But a lot of miles and time will elapse before you reach that point. Don't get caught up in Porsche Perfection Paralysis. Cats wore out in the past, and they will wear out in the future. So have engines, transmissions and chassis.

Try to have some fun anyway.