5w30. I'm in Penrith so it's warranted. Penrith Subaru supply 5w30 Castrol Edge.

 

That's not really excessively hot. I wouldn't go any higher than 5w30, unless you're seeing some really high oil temps, in which case an oil cooler would probably be a better idea. Without increased oil temps, the viscosity isn't dropping, so no need to go higher to compensate.

We get summer temps that high here (and winter down around -12C or less). Operating oil temp doesn't change much unless running the engine hard for prolonged periods. Just short shifting during hard street driving keeps the oil temp from climbing.

It does take longer for the oil temp to come up to operating in the winter, so I switch back to 0W20 by the time winter is in full swing.

On track it leveled out at 242F for me during about 15 mins of pretty hard driving. Ambient was about 30C that day.

 

5w30 with a stock engine

 

I'm in QLD and use Penrite 5w-20 in the street, and 5w-30 or 5w-40 on track.

 

Doesn't 0W-20 have a better higher temp rating than 5W-20?

 

5w-30 sounds fine for you, 5w-20 is pushing it on hot days and 5w-40 is overkill if you drive your car normally as a daily.

 

5w30 here also, no oil burn and more than capable to suit Adelaide’s temp range of 0-45c weather

 

Sorry reviving an old thread but I haven't been on here for a long time.

Penrite Enviro+ GF-S 5w-30 is 100% the way to go in Australia for a GR86/BRZ under warranty, and if not tracked, after warranty too.

Looking at the specs, it could probably pass as a 0w-30. Absolutely zero concerns about cold start viscosity. It's GF-6A and API SP Resource Conserving certified which is very rare in Australia so you know it ticks all the boxes for the manufacturer's standards and great peace of mind for warranty.

I may switch to a 0w-40 after the warranty runs out but for now, this stuff is the best.

 

Penrite Enviro+ GF-S 5w-30 is 100% the way to go in Australia for a GR86/BRZ under warranty, and if not tracked, after warranty too.

I actually used that Penrite GF-S 5W30 for a track day a few months ago, oil temps were very stable. As ambient temps were only in the low 20's probably any 5W30 would have been ok. Easy to recommend though, and currently half price at Supercheap!

Had my car serviced at Subaru last week, asked for 5W30, and they used Castrol Edge A3 5W30.
Oils with an ACEA A3 spec (also endorsed in the Owners manual) may offer better hot weather/hard driving protection as they are stable, stay in grade, with HT/HS ≧ 3.5. Edge A3 has a slightly higher viscosity at 100C vs GF-S, the latter probably has slightly better economy.

 

I'm actually taking my BRZ for a service on Wednesday at the dealership (I know dealership service, but while under warranty I prefer to get the yearly log book service done while under warranty). I plan to ask them if 5W30 would be better than 0W20 and would they put 5W30 in.

 

If you ask them if 5W30 is 'better' than 0W20 they will probably say no, since the latter is the 'recommended' oil.
However if you drive your car hard, and bearing in mind we'll be coming into summer shortly, then 5W30 is going to offer better engine protection. If you ask them to use 5W30 they probably will, my Subaru dealership was fine doing that.
If there is any push back, refer them to page 374 in the manual where it states:
"However, in hot weather, oil of higher viscosity is required to properly lubricate the engine."

 

5W30 year round, I see no advantage in using water weight 20 oils for any performance car. All you get is a higher chance of spinning a rod bearing.

 

Absolutely. 0W20 oils don't make much sense in Australia, unless you're chasing fuel economy at the expense of more high temp protection.
Not to mention there is nowhere in Aus where temps fall below or even approach the effective lower limit (-30ºC) of 5W oils.

 

I have been using 5w40 since my first oil change. Not risking my car to thin out on oil.