Hi al_KARA, mate it's a minefield out there, I see your concern.
You want to stay in warranty (SN OR GF-5, 5W30, full synthetic), but as others have stated there are "Approvals" / "Specifications" which usually means they have passed the test and are official products. But there is also "exceeds" / "suitable for" which usually means they are good products but without the official stamp required for your warranty.
I would use Penrite Pro 5, 5W-30, full synthetic, with API SN and ACEA C3, as well as other things like BMW LL-04. This is a good high HTHS oil for your application and drain interval. You should have no mechanical or warranty issues. This is my first choice.
My second choice is valvoline SynPower DX1, 5W-30, full synthetic, which is API SN, ILSAC GF-5 and dexos1. This will keep you in warranty, but has a lower HTHS than the Penrite above. So I believe the Penrite will protect you more in spirited driving.
Now I had a look at a lot of the other oils, all good oils mechanically, but they may cause warranty issues. (All the oils below are full synthetics)
Valvoline SynPower XL-III, 5W-30, it's ACEA C3 but No API Sx rating.
Shell Helix HX8, 5W-30, it's API SL and ACEA A3/B4
Castrol Edge 5W-30 A3/B4, it's API SL and ACEA A3/B4
Castrol Edge 5W-30, it's ACEA C3 but has no API Sx rating
The issue here is that there is a Phosphorous limit to be API SN in a 30 weight oil (but not in a 40 weight oil). The SL & A3/B4 oils above meet the API SN quality requirements, but exceed the phosphorous limits, so they are not official SN products. They do meet things like MB 229.5, which is a higher manufacturer standard, but that's not API SN (even though it's better). Many of the C3 oils are made for diesel cars, so even though they are good oils and suitable for your application, they haven't bothered to get them API SN certified (petrol), since it's not the market they are selling to.
My third choice would be Castrol Edge 5W-30 A3/B4, or Shell Helix HX8 5W-30, both are great oils, but "only" API SL, so warranty issues.
My fourth choice would be any the two C3 only oils listed above (SynPower XL-III or Edge 5W-30 C3). Also great oils for your drain interval, but no SN or GF-5, so warranty issues.
There might be more out there, but I think you get the idea.
Now I still believe the Penrite Pro is a workshop range of oils, so you may have trouble finding it in less that 200L quantities
http://www.penriteoil.com.au/engineoils-products.php?id_categ=1&id_products=22
But there might be something similar from Penrite under a slightly different name. Or maybe you can source it OK.
let us know how you get on.
