From: SMS on
Sophie wrote:

> I'm still waiting to see proof of a real world test where this proven.

You need to understand how a catalytic converter works. Phosphorus
destroys the catalyst. Hence the API lowered the phosphorus limit in
motor oil.

You can start your learning process by reading
and ""

If you want to test it, go buy a vehicle that burns a quart of oil every
3000 miles (well within manufacturer specs), and run it with non API oil
like Amsoil for 100,000 miles.

Until then, don't be echoing Amsoil's marketing material. If you have
proof that phosphorus doesn't destroy catalytic converters it's up to
you to post it, since you're the only one that is in denial. Of course
there is no proof of this, as you well know. That is why it is so
important to not use non-API certified oils in vehicles with catalytic