[Crumpler]

Not to introduce a firebomb, but what does the collective say about Castrol GTX high zinc 20w-50?

This is the first time I have seen it, but maybe I am late to the party.
I traditionally use Royal Purple 20w-50 HPS in the 928, but it requires delivery and certainly is not cheap.
The GTX is less than half the price.
Quick search landed me in various tech forums, with a wide range of feedback. Castrol apparently doesn’t have tech sheets as per exact zinc content, which makes me suspicious. But what the hell is the right zinc content anyway.

[worf]

But what the hell is the right zinc content anyway.

Roughy 1000-1200 ppm.

Here’s the MSDS for your Castrol:

https://msdspds.castrol.com/bpglis/Fusi ... BYBE6A.pdf

It’s 1400 ppm.

IIRC too much zinc is bad for cats.

[Crumpler]

Got it. Thanks Dave.
I’m going to try it and I will update with impression.

What’s a catalytic converter buddy?

[N_Jay]

VR1 20-50 is also 1400.

$27 for 5Qt from Amazon or Walmart.

EDIT:
Thought all VR1 was synthetic, but just noticed the synthetic VR1 is only in quarts and is also 1400 zinc.
Obviously a good bit more.

[maddog2020]

But what the hell is the right zinc content anyway.

Roughy 1000-1200 ppm.

Here’s the MSDS for your Castrol:

https://msdspds.castrol.com/bpglis/Fusi ... BYBE6A.pdf

It’s 1400 ppm.

IIRC too much zinc is bad for cats.

I’m more of a dog person anyway