In article , mike wrote:
On 26-03-2021 20:34 Scott Dorsey wrote:

Because
if your car was made in 1990 then the oil described in the service manual
is no longer being manufactured.

Stop being silly.
It gets better with each designation.
Sometimes it matters. Sometimes it don't.

Mostly it gets better. But I notice that you completely removed all of my
points about ZDDP.

The base oil gets better, but the additive package changes in ways that
may or may not be an improvement depending on your requirements.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."