[Stucks]

what is everyones favorite high zinc content oil run in the n54?

[AlanAZ]

Originally Posted by Stucks

what is everyones favorite high zinc content oil run in the n54?

Late reply, but M1 0w40 has high levels of ZDDP. (Suitable also for older flat tappet motors -- I'm using it in my gfriend's higher mileage QX4 in part for the high ZDDP levels help in reducing wear -- I'm using GC 0w30 in my 325.)

[AlanAZ]

I found this:

1. The Mobil 1 15W-50 (P/Zn levels 1200/1300 ppm) I used to use in my previous cars (before the Bimmer) is now discontinued. It is rated by Mobil as suited for "HT/HS applications, Racing and Flat tappet applications"

2. It seems you can't get any motor oil in California that has any API certification older than SM. Even the diesel oils are SM.
Mobil 1 0W-40 SM has P/Zn levels of 1000/1100. Not bad but less than the old 15W-50.
Mobil 1 0W-20/0W-30 SM only have P/Zn levels of 650/750 ppm, typical of the new API SM oils.

3. The API SM oils are the ones where the ZDDP extreme pressure anti-wear additive has been reduced. Supposedly this was done so that the new car manufacturers can meet the mandate that the exhaust catalysts last 120k miles and that they warranty them for that period of time.

a) Supposedly the Phosphorus content in the old oils with ZDDP can contaminate and reduce the effectiveness of the exhaust catalysts. So the Zn/P levels in SM oils are reduced to below 800 ppm.

b) No one seems to claim that the ZDDP "kills" the catalyst. Merely that their life is reduced.

c) This is only really an issue if your engine BURNS OIL. Otherwise how is the ZDDP going to get to the catalysts?

d) I've got a BMW with 167k miles on its original engine. It has probably been running the original oil formulas with ZDDP levels around 1200 ppm since it was new. It easily passed it's last smog test, and that was before the extensive maintenance that I've done to it.

e) So what the eco-weenies are saying to me in essence:
Your car has been running motor oil with the higher ZDDP levels since it was new (2000). Your engine hasn't worn out, and your exhaust catalysts are still effective. But because some people's engines burn oil which means some peoples catalysts will be reduced in effectiveness which means some peoples cars will emit more pollution - we are going to keep you from buying the oil that will help your old BMW engine last many tens of thousands of miles more.

http://www.bimmerforums.com/forum/sh...ifter-Tick-etc

[Stucks]

Ive talked to a couple high horsepower n54 guys and some of them have run german castrol 0w30/0w40, and a couple others have run joe gibbs dt40 due to the increased zddp content (1400ppm)

[AlanAZ]

Originally Posted by Stucks

Ive talked to a couple high horsepower n54 guys and some of them have run german castrol 0w30/0w40,

What's the P/Zn levels of GC 0w30? Since that's what I run.