'21 Sienna 2.5l hybrid 202k mi; PU 0w-20 4.6k mi

[Hohn]

You raised a great point about the durability of these engines. Toyota and Honda must have considered fuel while designing these motors. Maybe I shouldn't worry and just keep going. I have made it to 200k, the engine runs perfectly fine.

Sienna Dude, while I don’t think anyone wants to see that kind of fuel dilution, I think you really need to step back and focus less on the supposed problem of dilution and more on what you know to be true:

• Your van has made it to 200k with no real issues. The consumption is well in check, the engine is performing quite well
• The wear indicators in UOA are showing very low wear.

In other words, if the fuel dilution was an actual problem, you would have seen something in 200k miles other than high fuel on your UOA. TBQH, if you weren’t running UOA, would you think for a moment there was any problem?


The low temps are a feature, not a bug in many ways. Yes they make it harder to burn off fuel dilution. But those same low temps also assure that:

• Your oil oxidation rate is super low
• Your viscosity is much higher in the running engine than the KV100 would indicate.
• The low temps slow some of the chemical reactions that make fuel dilution such an issue. (I.e. carboning).

All the hand wringing over loss of viscosity is not warranted when your oil temps are running 170F or so. Converting KV100 of 8.8 to KV70 (165F) would put you at 17.65cSt based on the published API SN data sheet values for KV40 and KV100. (I can’t find SP right now). That’s well into 50 grade range!

YOU DO NOT HAVE A LOW VISCOSITY PROBLEM.

Keep doing exactly what your doing and don’t sweat the non-issue of fuel dilution. your viscosity in actual engine running conditions is far above what the KV100 would suggest. Heck, you might be able to tolerate 10% or more dilution!

Dilution in and of itself is not a problem. Unchecked, it can certainly cause problems because fuel is a contaminant. But that’s why we change oil.

Given your steady usage with consistent temps, honestly you could probably make a mineral or blend 0w20 work on shorter ODIs quite cost-effectively, changing the filter every other time.

You are an attentive and conscientious owner and could use about any oil successfully. You’ve done well to get you this far, don’t question what’s worked for 200k.

 

[Sienna dude]

Sienna Dude, while I don’t think anyone wants to see that kind of fuel dilution, I think you really need to step back and focus less on the supposed problem of dilution and more on what you know to be true:

• Your van has made it to 200k with no real issues. The consumption is well in check, the engine is performing quite well
• The wear indicators in UOA are showing very low wear.

In other words, if the fuel dilution was an actual problem, you would have seen something in 200k miles other than high fuel on your UOA. TBQH, if you weren’t running UOA, would you think for a moment there was any problem?


The low temps are a feature, not a bug in many ways. Yes they make it harder to burn off fuel dilution. But those same low temps also assure that:

• Your oil oxidation rate is super low
• Your viscosity is much higher in the running engine than the KV100 would indicate.
• The low temps slow some of the chemical reactions that make fuel dilution such an issue. (I.e. carboning).

All the hand wringing over loss of viscosity is not warranted when your oil temps are running 170F or so. Converting KV100 of 8.8 to KV70 (165F) would put you at 17.65cSt based on the published API SN data sheet values for KV40 and KV100. (I can’t find SP right now). That’s well into 50 grade range!

YOU DO NOT HAVE A LOW VISCOSITY PROBLEM.

Keep doing exactly what your doing and don’t sweat the non-issue of fuel dilution. your viscosity in actual engine running conditions is far above what the KV100 would suggest. Heck, you might be able to tolerate 10% or more dilution!

Dilution in and of itself is not a problem. Unchecked, it can certainly cause problems because fuel is a contaminant. But that’s why we change oil.

Given your steady usage with consistent temps, honestly you could probably make a mineral or blend 0w20 work on shorter ODIs quite cost-effectively, changing the filter every other time.

You are an attentive and conscientious owner and could use about any oil successfully. You’ve done well to get you this far, don’t question what’s worked for 200k.

You're right, the thing runs like a clock, I'm still hitting EPA MPG numbers hauling heavy people and luggage. Thanks for saving my money on another UOA. Case closed lol.

 

[Sienna dude]

Oh, and the last but not the least, it does not burn a drop of oil

 

[Hohn]

Oh, and the last but not the least, it does not burn a drop of oil

Which speaks well to the condition of the rings as far as deposits and carbon packing.

Fuel dilution is only a problem when it degrades the oil properties sufficiently to create a problem with cleanliness or wear. You are seeing no issues with either. Hence, I conclude your current dilution rates are acceptable when measured by the votes cast by the engine itself.

 

[Sienna dude]

Which speaks well to the condition of the rings as far as deposits and carbon packing.

Fuel dilution is only a problem when it degrades the oil properties sufficiently to create a problem with cleanliness or wear. You are seeing no issues with either. Hence, I conclude your current dilution rates are acceptable when measured by the votes cast by the engine itself.

I used HPL 0w16 couple of months back and sent the filter for analysis. It should come on Youtube in a few weeks. Once that filter looks as good as the previous filter than it is confirmed my engine is as clean as it gets. I am excited for that video.

My filter with Pennzoil looked awesome

 

[oilstained]

Converting KV100 of 8.8 to KV70 (165F) would put you at 17.65cSt based on the published API SN data sheet values for KV40 and KV100. (I can’t find SP right now). That’s well into 50 grade range!

This is very interesting stuff.

 

[ATex7239]

This is very interesting stuff.

And after years of trashing Toyota for moving to ultra thin oils it turns out they designed the engine to properly handle it.

 

[pbm]

I'm sure there are many Sienna Hybrid owners (as well as Camry and RAV4 Hybrids which use that same engine if I'm not mistaken) who never get an oil analysis and just bring it in to Toyota, Jiffy Lube etc...every 5K. They don't know anything about 'fuel dilution' and will probably sell their vehicles with high miles before ever having an engine issue. I trust Toyota engineering more than most other car makers so I wouldn't sweat the fuel dilution and just enjoy that great MPG you are getting.

PS: I do agree with your use of 0w20 and PUP is certainly a good one.

 

[ATex7239]

@Sienna dude

A

Thread '‘21 Toyota Sienna Hybrid / A25A-FXS / 80,700 miles / Pennzoil Platinum 0w20 / 5,600 miles'

Apr 5, 2024

Winter run of 5,600 miles from Dec ‘23 to Mar ‘24. OA lists oil as PP 0W16 on report but it is actually PP 0W20. Previous data from Dec ‘22 to Mar ‘23 is with PP 0W16 for 5,000 miles. Viscosity stayed around 7.0 cst @100c this time which is about the range I was hoping for going up. The Toyota seems to dilute in colder weather, but does fine during the warmer months. Likely to stick with PP 0W20 during the winters to mitigate.

• ATex7239
• Replies: 8
• Forum: Used Oil Analysis - Gasoline

• 
• 

Here is a link to UOA’s from our previous Sienna (totaled at 90K) which used mostly Pennzoil Platinum 0W16 and 0W20 with great success despite fuel dilution.

It was such a good vehicle that we got another one to replace it. I’m glad you showed up to this forum with all this data on a high mileage Toyota A25A. The info and especially the temp reads are very helpful.

Turns out after all the years of naysaying and hand wringing on this forum over 16 and 8 oils, Toyota did it right. With the lower engine operating temps these ultra thin oil are nothing to worry about.

 

[SC Maintenance]

I am sadly thinking of going back to 0W-20 instead of 5W-30 on my Rav - same engine but the ICE variant based on this thread.

I guess I need to track oil temps first.

 

[ATex7239]

I am sadly thinking of going back to 0W-20 instead of 5W-30 on my Rav - same engine but the ICE variant based on this thread.

I guess I need to track oil temps first.

If you do please post it.

When people show up asking about the thinner oils or the old guard brings out the torches and pitchforks we can just point to the data. Basically the same thing we did to the folks freaking out about the “electric” oil pump theory.

 

[fantastic]

The report looks good outside of fuel. I don't think there is anything worth changing yet.

 

[SC Maintenance]

If you do please post it.

When people show up asking about the thinner oils or the old guard brings out the torches and pitchforks we can just point to the data. Basically the same thing we did to the folks freaking out about the “electric” oil pump theory.

I will need to do a lot more research first. The fact the oil doesn't get to temp is only one piece. It does make me think about it more though.

This engine - at least in ICE form has an algorithm that drops oil pressure in low RPM / low load situations. This is primarily why I run 5W-30 - 16 PSI oil pressure is disconcerting even under very low load. Thicker film strength can help with that to some degree.

Clearly its a very good engine either way.

 

[ATex7239]

I will need to do a lot more research first. The fact the oil doesn't get to temp is only one piece. It does make me think about it more though.

This engine - at least in ICE form has an algorithm that drops oil pressure in low RPM / low load situations. This is primarily why I run 5W-30 - 16 PSI oil pressure is disconcerting even under very low load. Thicker film strength can help with that to some degree.

Clearly its a very good engine either way.

View attachment 285535

I think flow is more important though. And given it runs colder (ie the oil will be thicker) the film will be there. Just my 2 cents.

 

[SC Maintenance]

I think flow is more important though. And given it runs colder (ie the oil will be thicker) the film will be there. Just my 2 cents.

So at 70C with the pump held at 16PSI, how much more flow do you really get with a 20 weight vs a 30 weight. Thats the question. Your giving up a lot of film thickness, but is the flow really much better?

 

[ATex7239]

So at 70C with the pump held at 16PSI, how much more flow do you really get with a 20 weight vs a 30 weight. Thats the question. Your giving up a lot of film thickness, but is the flow really much better?

At 70C both are plenty thick enough. Nothing is lost but also nothing is gained it seems.

 

[Sienna dude]

So at 70C with the pump held at 16PSI, how much more flow do you really get with a 20 weight vs a 30 weight. Thats the question. Your giving up a lot of film thickness, but is the flow really much better?

Did you go through that detailed comment here? Most of the times our oil behaves like 50 and 40 grades. Worry about the fuel, not the viscosity. I made it this far on oil as thin as 5.9 centistokes. All oils start very thick when cold, and this engine doesn't let the oil get thin.

 

[SC Maintenance]

At 70C both are plenty thick enough. Nothing is lost but also nothing is gained it seems.

So is there a film thickness vs temperature and viscosity graph floating around here somewhere?

 

[Sienna dude]

If you run a 12 centistoke thick 0w30 in this engine, you are unnecessarily stressing it. 0w30 at 150 degrees doesn't sound great. The engine and oil pump would be working hard needlessly.

 

[SC Maintenance]

Did you go through that detailed comment here? Most of the times our oil behaves like 50 and 40 grades. Worry about the fuel, not the viscosity. I made it this far on oil as thin as 5.9 centistokes. All oils start very thick when cold, and this engine doesn't let the oil get thin.

Define "behaves like a 40 and 50 grade". I would need a chart not a generalization.

Viscosity vs temperature behaves like this. You would need to figure out where your running and the film thickness at each point. Generalizations are just that.

Yours being a hybrid it might have a much different dilution affect. It runs in a much more agressive atkinson cycle which can contribute to dillution. Its also a much heavier vehicle, used under much harsher conditions than my family car.

Not so much worried about mine lasting, clearly an academic discussion.