It's done 5000klm and I've been all over the net reading about whether to stay with factory recommended oil and how the motor clearances are specific to 0w-16 and how can the engineers be wrong and the oil pump thing etc. I've had engine builders tell me the tight engine clearances are all melaki and they haven't changed in years, it's all about marketing and keeping fuel consumption down and power up. So I dropped the oil last weekend and put Penrite GF-S 5w-30 in with an OEM filter. I actually noticed a few things up front. Before the motor would kick in and sound like a lumpy bag of bolts, now it's smooth and quieter. Also the fang power from standstill is down slightly maybe 10% on wot. The fuel consumption kicked up .1 litre per 100klm to 6.1. Over here in Au the winters are reasonably mild and to get the next factory oil change I'd have to wait till November or 15000 k, which I feel is way to long on 0w-16 even with all the additives which is another argument.

I'm interested what others on here might think There's also 0w-20 but I don't see the point just for that.

 

my mostly uneducated rule of thumb, for regular driving I'd only go 1 step thicker. so if the car asked for 0w-20, go to 0w-30. I wouldn't skip to 0w-40. but going from a 16 to a 20 is a smaller step, so maybe 30 is ok in this situation? I would stay with the same cold rating though for cold starts (even though you live in hot upsidedown land). so 0w-30 instead of 5w-30. the guy in the vid below will recommend you do oil analysis on your oil to check how its wearing. but woulda been good to check the 0w-16 first to have something to compare it to...

another thing that I've always wondered about with (some?) hybrids is that there's not really time for engine warmup. especially with plug in hybrids that can drive 20-50ish miles on electric only and only kick in the engine when you request enough beans (floor it) that it needs to kick in the gas engine too. so you've been driving for 10 minutes already in EV only but the engine is still cold, you floor it, and suddenly the engine goes from off and cold to high load/high rpm...? thats gotta be horrible for the engine.. but speaking of thin oils, I can see (again uneducated how I think things work but could be wrong) how a thin oil would be better in a situation like that over a thick oil...?

oil engineer in a similar situation:

 

Yeh, there's some hybrid standards I read you have to have in the oil, which I can't find in 0w-30

• SP Resource Conserving, API SN Plus Resource Conserving
• ILSAC GF-6A

On 5w-30, I've also noticed the hybrid petrol motor kicking in more often, than with the 0w-16 which probably accounts for the slightly higher fuel consumption. I also don't understand how the engine can stay warm when running on battery all the time, but the car seems to heat up like normal, maybe it's a fake reading to keep the owner happy. The electric motor to petrol motor transition of the Toyota is virtually seamless so initial cold flow is probably important but 0w to 5w I wouldn't have thought was much of a big deal and my concern is on trips running 0w-16 might start impacting motor wear. So I'm thinking might drop a couple of litres of 5w30 out the sump and mix in some 0w-20 of the same brand that way I'll get a bit more flow and also be protected