Originally Posted By: supercity
It's Fuel Saver GF-5.
I'm glad to see healthy TBN. It seems to have done well after 6 months, I think I could try GTX 10w30 next time.
Hey Mate,
Yes a very strong TBN (6.3 after 6600 km) and lots of zinc (974 ppm).
Castrol Australia seem to have a heavy hand when it comes to the add pack, they seem to approach the ILSAC limits from above, rather than below which may be more typical in other countries.
At KV100 = 9.0 cSt you have just gone out of grade (9.3 cSt limit), but that is not a big problem as these engines are mostly run on 20 grade oil in North America from what I have read here on BITOG. It's probably fuel dilution due to lots of short tripping which I assume is the severe service you are talking about.
I think the new Castrol GTX 10W30 "UltraClean" would be a great choice for this engine. It's SN and GF-5, plus Castrol list it as a semi-synthetic on their Oz web site.
BTW nice low iron at 8 ppm.