2026 Prius 0W-8 oil!!!!

[50yr Street Mech]

0W8 ?!?! I'm sorry, that water would not withstand the Southwest temps of 110 degrees in the shade ( like Las Vegas), or the deserts of Arizona. Could be useful for lets say....Siberia, Alaska ( in the winter months), North & South poles....etc...LOL Will they ever stop with this nonsense one day ?!?! Yes they will..how stupid of me...an oil free engine !!!!!! The fuel will double as a lubricant !!!!!

 

[bilibako2]

DIY here, our 24 corolla required 0W-8 which available at Walmart.My plan November to May at 0w-8 and warmer weather 0w-16 around 6 months interval, reset maintainnace light and not to bringing it in on their free 10k oil change.

 

[rondhol]

Toyota has variable oil pump on newer 2.0, 2.5 engines. They are probably calibrated for oil pressure with 0w8 and 0w16 oil. Using thicker oil may change the calibration and oil flow. Thinner oil flow faster and cool the engine better at the same oil pressure. Besides that, unlike GM, Toyota engines have no issues with the main bearing barely have any wear even after 300k+ miles. It has more problems with stuck piston rings from degraded/oxidized engine oil and additives. So, I won't put any oil thicker than 0w16 on 2.0 and 2.5L hybrid engines.

https://toyota-club.net/files/faq/16-01-01_faq_oil-pump_eng.htm

 

[rondhol]

copied

 

[JavierH19]

Toyota has variable oil pump on newer 2.0, 2.5 engines. They are probably calibrated for oil pressure with 0w8 and 0w16 oil. Using thicker oil may change the calibration and oil flow. Thinner oil flow faster and cool the engine better at the same oil pressure. Besides that, unlike GM, Toyota engines have no issues with the main bearing barely have any wear even after 300k+ miles. It has more problems with stuck piston rings from degraded/oxidized engine oil and additives. So, I won't put any oil thicker than 0w16 on 2.0 and 2.5L hybrid engines.

https://toyota-club.net/files/faq/16-01-01_faq_oil-pump_eng.htm

View attachment 295459

Not another calibrated oil pump comment.

The variable oil pump equipped a25a-fks for 2018 and newer vehicles hybrid or not allow you to use everything from 0w-16 to 15w-40

Edit - Same applies to the newer 0w-8 engines

 

[Pablo]

Toyota has variable oil pump on newer 2.0, 2.5 engines. They are probably calibrated for oil pressure with 0w8 and 0w16 oil. Using thicker oil may change the calibration and oil flow. Thinner oil flow faster and cool the engine better at the same oil pressure. Besides that, unlike GM, Toyota engines have no issues with the main bearing barely have any wear even after 300k+ miles. It has more problems with stuck piston rings from degraded/oxidized engine oil and additives. So, I won't put any oil thicker than 0w16 on 2.0 and 2.5L hybrid engines.

https://toyota-club.net/files/faq/16-01-01_faq_oil-pump_eng.htm

View attachment 295459

This is written as if oils don't gain viscosity with lower temperatures or another way to say it, as if 0W ratings are useless.

 

[rondhol]

I would like to see if the wear number on using thicker oil have a better wear. Otherwise, we are still guessing.
We all know at lower temp, the viscousity is much higher, exponentially. Toyota is very conservative and I doubt using what recommended 0w8 has negative effect.

 

[Pablo]

I would like to see if the wear number on using thicker oil have a better wear.

In general true, so BITOG goes with thick enough to pump and flow and give barrier film some margin.

For these magic 0W-8 engines, some data would be excellent.

 

[kschachn]

Toyota has variable oil pump on newer 2.0, 2.5 engines. They are probably calibrated for oil pressure with 0w8 and 0w16 oil. Using thicker oil may change the calibration and oil flow. Thinner oil flow faster and cool the engine better at the same oil pressure. Besides that, unlike GM, Toyota engines have no issues with the main bearing barely have any wear even after 300k+ miles. It has more problems with stuck piston rings from degraded/oxidized engine oil and additives. So, I won't put any oil thicker than 0w16 on 2.0 and 2.5L hybrid engines.

https://toyota-club.net/files/faq/16-01-01_faq_oil-pump_eng.htm

View attachment 295459

They aren't "calibrated" for a grade.

 

[50yr Street Mech]

Yeah, " magically throw a rod " while sitting in traffic & it's 105 degrees out....Oh, and the A/C is on full blast.

 

[kschachn]

I would like to see if the wear number on using thicker oil have a better wear. Otherwise, we are still guessing.
We all know at lower temp, the viscousity is much higher, exponentially. Toyota is very conservative and I doubt using what recommended 0w8 has negative effect.

Higher film thickness always reduces wear. What Toyota and others do is make engineering changes to the engine that allows it to tolerate a thinner oil without excessive wear.

All of which we pay for by the way. I often wonder if for the average consumer we ever recoup the cost on an individual basis. Toyota certainly does by CAFE standards, but there's no indication that filters down to the consumer.

 

[JavierH19]

To those that are curious https://www.lube-media.com/wp-conte...y-for-engine-oils-the-formulators-dilemma.pdf

 

[ARCOgraphite]

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.

Once the journal floats that clearance is halved approximately. I would spec 0.0010+.0005" as a bushed slip/sliding working fit on machines I have designed. Issue here will be resonances, ringing and flexure - precise balance of the reciprocating assembly for the journal(s) to run true.

Another thing to keep in mind is that VOA of 0W8 has shown higher EP/AW treat rates than the 16 or 20 grades.

I would hazard a guess if someone jacked the Pruis and ran from LEO running the ICE at redline for any long minute that thing may expire. if not today, maybe tomorrow.
I had a new 2025 Subaru Impreza base a couple three months ago. After one vigorous run up Interstate 93 North during the afternoon commute the engine had developed a loud rap by the time i got home. Factory 0W16 and those CVT that spin the motor to redline when spurred. Oh my.

- Arco

 

[rondhol]

Thanks for sharing. What shocking is 0w16 has lower friction than 0w8 during the test. I did not find what engine was used here. 1.6L GDI engines, made by who?
More data, tested in actual Toyota or Honda engines will be more convincing. For now, I feel that 0w8 will work just fine if Toyota or Honda spec that. The wear from clogged piston rings is more alarming for me than anything else on these hybrid cars.

 

[50yr Street Mech]

EVERYTHING filters down to the consumer, not in just cars or oil either. You know the old sayin " Sh-t rolls downhill "

 

[skyactiv]

Yeah, " magically throw a rod " while sitting in traffic & it's 105 degrees out....Oh, and the A/C is on full blast.

Do you have any real world experience on modern engines specifying 0W8 and/or 0W12?

 

[50yr Street Mech]

My guess on the coked rings would be too long between OCI's. 10k-15k OCI's is really pushin the envelope in my book. I don't care what kind of oil or filter is in it.. Too long. 5k-8k tops. Just did a 650 mile OCI on my 13' Honda, right after a heat wave. The oil was COOKED...Looked like it was in there for 5k !!

 

[50yr Street Mech]

No, I do not have experience with engines using this oil. My cars are too old. Yes, I do believe the engines are engineered to run on these thin oils...but I guess you can just say I'm old school, because, I'm old LOL....I'm sure R&D did their thing before mass producing the engines. I get it, really. Just tough teachin old dogs new tricks LOL...The engines will be fine as long as the owners follow the maintenance schedule. That's 1/2 the battle I think, owners letting OCI's go too long. I mean, I was brought up on dino 10W40 in my old V-8's. All it did was clog the drain back ports under the valve covers and sludge up everything. I was happy when synthetics came out. No more diggin head drain back ports to clear the sludge. Messy all day job that was.

 

[ARCOgraphite]

Nope they gonna give up no matter whatever you do.

In this order: Subaru first, Toyota second and Honda a distant third.

 

[KEVINK0000]

Higher film thickness always reduces wear. What Toyota and others do is make engineering changes to the engine that allows it to tolerate a thinner oil without excessive wear.

All of which we pay for by the way. I often wonder if for the average consumer we ever recoup the cost on an individual basis. Toyota certainly does by CAFE standards, but there's no indication that filters down to the consumer.

I would say the answer is no, definitely not. Especially the buyer of the new car. That brother takes a mighty big hit. The vultures that buy stuff at the bottom of the depreciation curve like me, might possibly benefit.