Magnesium and japanese cars

[Primus]

There is quite a strange Petronas statement in respect of magnesium when they decribe their Syntium 5000:

"It is especially low on undesirable elements such as phosphorus, chlorine, sulphur and sulphur ash, and there is no magnesium additive present.. The absence of magnesium is something which is of particular importance to Japanese carmakers, and reduces the incidence of deposits"

Well, may be magnesium in oil is really bad, but why is it particularly bad for japanese engines ?

 

[TR3-2001SE]

Don't know the answer to this but Mobil 1 has a slight amount of magnesium ie 20ppm but the Delvac 1 diesel oil has much more like 500ppm.
Sounds like this might be marketing hipe?

 

[Road Rage]

The factory fill analysis of a Honda V6 showed about 25 PPM of magnesium, and plenty of moly, zinc, and phos - so while Honda may want an SL-rated oil later in the engine's life to save their precious cats, they apparently want some level of magnesium in their engines, and lots of phos early on.

I think Petronas is hyping this - and it is a non-player here in the US anyway, where I believe there are more than a few Accords sold each year.