Wow ! Nice Tangent Shannow, good web site. I had no idea the old Rover 3.5L V8 was a Buick. There you go.
A good write up on the Aussie Falcons too.
Above, I was trying to practice a little cultural sensitivity, probably very badly, I think Dexos is a better oil standard than just SN. However I'm a ACEA A3/B3/B4 type of guy and would run it in everything. Talking to Garak, it seems ACEA is a bit rare over there (with a few obvious exceptions like M1 0W-40), but the HDEOs (with CI. CJ, E7, E9) seem to be common and affordable.
Me ? Here? I would probably run a mineral HDEO 15W-40 like Delo or Castrol RX. Over there? Not sure about all these winter cold start problems they talk about. To me winter is the nice time of year, I'm sweating my ring off in summer. But their synthetic HDEOs like Rotella T6 seem to have a 5W-40 and should start better in a real winter. Same with something like SynPower 5W-40 which is A3/B4.
Where I live, years ago I would happily use Penrite 20W-60 all year round, and probably still could. But I'm going light now days, and more interested in 15W-40.