Bought a new 2025 toyota crown signia last Oct it came with 0w-08. I changed the oil at 1K and put in 0w-20. It runs fine on it. I will use 0w-20 all the time the rest of the time I have it. 0w-20 works for me because I have other vehicles that run on 0w-20 don't need another oil weight around. And yes my oil cap has 0w-8 on it. My signia is a hybird and the engine turns on and off a lot around town like your prius will. I'm sure 0w-16 will be fine if you want to run that.
2026 Prius 0W-8 oil!!!!
- Thread starter dbvettez061
- Start date
As I suspected! 0W-8 is just a plot to get everyone to use 0W-20!!!
20 is the new 30.
0W-40
Not sure what you are saying here. A grade is a grade.surprisingly 0w8 is not 40% as thick as 0w20...
In fact there is one specific viscosity that could be called 0w12 0w16 and 0w20 simultaneously.
I think he’s alluding to the overlap between grades. For example 7.0 cSt @ KV100 could technically fall into 12, 16, or 20 on J300 due to the overlap and it wouldn’t be substantially far off from the high range of 8.
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FWIW bearing clearances are similar on a new car as they were in a Small Block Chevy. I've been using 5W-30 in my Jeep 2.4 Multiair and Cadillac XT4. IMO 0W-8 or 20 for that matter doesn't give you the margins for error if you get fuel dilution with these modern motors.
FWIW Toyota specifically has D4S which uses port and direct injection and also there is evidence that these engines run cooler at operating temperatures than most designs. Now I am not saying that this could completely mitigate effects or that it is fine. But to me at least it seems like using the right 20 in an engine spec for 8 with those factors accounted for would put you in a similar position to using 30 in an engine spec for 20.
Do people run 4 qts in this engine?
These ultra-thin oils are viable only because of very low average oil temps and highly transient duty cycles.
Personally, I'd be using HPL 10w20 in this application. Super low volatility but still thin enough for a highly transient cycle where oil pressure delay is important, it has a super combination of HTHS/KV100 and volatility.
On EDIT: Apparently Toyota has been able to produce match fit bearing clearances in the 10-20 micron range. So we're talking one half to one quarter of one thousandth of an inch. I guess that's what it takes to make the 0w-8 function well in the mains and rods.
The other main design aspects are extremely fine surface finishes-- Superfinish or DLC used many places.
Personally, I'd be using HPL 10w20 in this application. Super low volatility but still thin enough for a highly transient cycle where oil pressure delay is important, it has a super combination of HTHS/KV100 and volatility.
On EDIT: Apparently Toyota has been able to produce match fit bearing clearances in the 10-20 micron range. So we're talking one half to one quarter of one thousandth of an inch. I guess that's what it takes to make the 0w-8 function well in the mains and rods.
The other main design aspects are extremely fine surface finishes-- Superfinish or DLC used many places.
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The one I posted is from the 1.5L 3 cyl m15a which came out first not the 2.0L 4 cyl m20a but is identical architecture and clearance wise. The m20a holds an extra quart. I know they sell the current prius in japan with two engines with the 2.0 being the larger one. I wouldn't be against an m15a equipped prius or corolla in the US. it would still have enough power but be more efficient.
Toyota has been know to change oil recommendations in the middle of a model cycle. The fourth generation Prius originally called for 0w-20 but that recommendation was revised to 0w-16. Similarly the fifth generation Prius, model years 2023 onward originally called for 0w-16 but apparently now the recommendation is 0w-8. I was tempted to go with 0w-16 in our 2017 and 0w-12 in our 2023 at the last change but decided to stay on the reservation for now.
NOACK. That’s one of the bad Transformers, yeah?
I would go 10w-60 in it
Noack.
go for 0w-16
Probably, might as well put in some corn oil, its a Toyota after all, it will be fine.
Bearing tolerances, maybe? Anyways, I'm not a machinist (but my son is and I don't have his knowledge) but 20 microns is .0007874 inches.
No kidding.
Oh, to be new here again.
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