Toyota (TGMO) 0W-20 SN nice and thick when hot

[Gokhan]

I got my UOA results on the Toyota (TGMO) 0W-20 SN. The results were posted here.

I was pleased to see that the hot viscosity of Toyota (TGMO) 0W-20 SN is very strong at 9.0 cSt. Most 5W-30s will shear to a 100 C viscosity smaller than 9.0 cSt. Therefore, Toyota 0W-20 is providing an added safety margin of viscosity protection than most 5W-30s.

On top of that, having an ultrahigh viscosity index (VI), around 220, the cold viscosity is as small as it gets, which is also giving great cold-engine protection.

Best of both the hot and cold worlds!

 

[147_Grain]

Your results might be better served in the Used Oil Analysis Section:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2959013#Post2959013

___________________

The higher than normal viscosity might be from the much thicker / leftover 15W-40 diesel oil from the last LOF change.

The sodium is likely from a small leak from the well-worn headgasket. Would recommend you stick with 5-6K oil changes with 5W-20 or even 5W-30 weight oil in the Southern California heat. Your engine has 250K on the clock and might benefit from a 5W-30 weight oil.

 

[Gokhan]

Originally Posted By: 147_Grain
Your results might be better served in the Used Oil Analysis Section:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2959013#Post2959013

___________________

The higher than normal viscosity might be from the much thicker / leftover 15W-40 diesel oil from the last LOF change.

The sodium is likely from a small leak from the well-worn headgasket. Would recommend you stick with 5-6K oil changes with 5W-20 or even 5W-30 weight oil in the Southern California heat. Your engine has 250K on the clock and might benefit from a 5W-30 weight oil.

The last oil was PYB 5W-20 SN, not 15W-40. It had a smaller UOA viscosity than that of TGMO 0W-20 SN.

 

[Gokhan]

Originally Posted By: 147_Grain
Your results might be better served in the Used Oil Analysis Section:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2959013#Post2959013

___________________

The higher than normal viscosity might be from the much thicker / leftover 15W-40 diesel oil from the last LOF change.

No, the last oil was PYB 5W-20 SN, not 15W-40. It had a smaller UOA viscosity than that of TGMO 0W-20 SN. Therefore, there is no leftover-oil effect. Even if there was, it would underestimate the actual viscosity, as the previous viscosity was smaller.

The results were originally posted in the UOA section. I posted here to bring attention to the viscometric properties of Toyota 0W-20 SN.

 

[Capa]

Very impressive. This oil is rated, IIRC, for about 10,000 miles. Do you believe, with the TBn level, that it could reach those miles?

 

[CMMeadAM]

Originally Posted By: Gokhan
I got my UOA results on the Toyota (TGMO) 0W-20 SN. The results were posted here.

I was pleased to see that the hot viscosity of Toyota (TGMO) 0W-20 SN is very strong at 9.0 cSt. Most 5W-30s will shear to a 100 C viscosity smaller than 9.0 cSt. Therefore, Toyota 0W-20 is providing an added safety margin of viscosity protection than most 5W-30s.

On top of that, having an ultrahigh viscosity index (VI), around 220, the cold viscosity is as small as it gets, which is also giving great cold-engine protection.

Best of both the hot and cold worlds!



According to Wearchecks VOA of the TGMO 0W20 SN oil, the VI is 216 ( 214 for the SM )
The VI@100C, cSt is 8.54 ( 8.8 for the SM ), and the VI@40C, cSt is 37.38 ( 39.3 for the SM )with a 6.84 TBN. In our experience, the TGMO 0W20 SM oil in a 2011 Prius has sheared down to 6.79 ( 28.56%... factory fill ) and was changed at 1234 miles.
Another change with 5010 miles resulted in a shearing of 13.76% ( 7.64 ) with a 385 F flashpoint and trace of fuel. The TBN was 5.0 with a TAN 0f 5.1.

 

[KrisZ]

Originally Posted By: CMMeadAM
Originally Posted By: Gokhan
I got my UOA results on the Toyota (TGMO) 0W-20 SN. The results were posted here.

I was pleased to see that the hot viscosity of Toyota (TGMO) 0W-20 SN is very strong at 9.0 cSt. Most 5W-30s will shear to a 100 C viscosity smaller than 9.0 cSt. Therefore, Toyota 0W-20 is providing an added safety margin of viscosity protection than most 5W-30s.

On top of that, having an ultrahigh viscosity index (VI), around 220, the cold viscosity is as small as it gets, which is also giving great cold-engine protection.

Best of both the hot and cold worlds!



According to Wearchecks VOA of the TGMO 0W20 SN oil, the VI is 216 ( 214 for the SM )
The VI@100C, cSt is 8.54 ( 8.8 for the SM ), and the VI@40C, cSt is 37.38 ( 39.3 for the SM )with a 6.84 TBN. In our experience, the TGMO 0W20 SM oil in a 2011 Prius has sheared down to 6.79 ( 28.56%... factory fill ) and was changed at 1234 miles.
Another change with 5010 miles resulted in a shearing of 13.76% ( 7.64 ) with a 385 F flashpoint and trace of fuel. The TBN was 5.0 with a TAN 0f 5.1.


That is why a single UOA is useless. Comparing that single UOA to other UOAs for different oils and different engine/applications/driving styles is even more useless.
Lets see several UOAs for this car with different oils and then the real discussion can start.

 

[JAG]

Coolant contamination thickens up oil so we don't know what the oil's viscosity would have been without the contamination.

 

[buster]

^ good point.

 

[INDYMAC]

This oil sheared to 7.6cSt@100C in my 2012 4Runner after 5K miles. It's not very shear stable IMO. But I will continue to use it and evaluate further.

 

[Gokhan]

Originally Posted By: JAG
Coolant contamination thickens up oil so we don't know what the oil's viscosity would have been without the contamination.

Yes, however, I am not 100% convinced that I have a coolant seep into the oil. It's certainly quite possible with a 28-year-old head gasket. I need to sample directly into the plastic bottle instead of the tin can next time to make sure that the sodium didn't come from washing the tin can with soap and the chromium didn't come from the plating of the can.

Ingredients in Simply Ivory: sodium tallowate and/or sodium palmate, water, sodium cocoate or sodium palm kernelate, glycerin, sodium chloride, fragrance, one or more of the following: coconut acid, palm kernel acid, tallow acid or palm acid, and tetrasodium EDTA.

Ingredients in can plating: chromium, zinc, etc.

 

[Hokiefyd]

Is it possible that it had sheared down in Gokham's engine (say to 7.5 cSt), and had already started to thicken back up due to oxidation by the time it was UOA'd?

 

[Gokhan]

Originally Posted By: Hokiefyd
Is it possible that it had sheared down in Gokham's engine (say to 7.5 cSt), and had already started to thicken back up due to oxidation by the time it was UOA'd?

I would somewhat doubt that. We're talking about a high-quality modern fully synthetic oil here and I think my engine is fairly easy on the oil.

Also, most other posters are talking about the SM variety, which is completely different than the SN variety, the latter being significantly superior, with much better, less-shearing VIIs.

 

[andrewg]

TGMO?

 

[martinq]

Originally Posted By: andrewg
TGMO?

Toyota
Genuine
Motor
Oil

... even though it's an Engine Oil and not really suitable for motors.

 

[CMMeadAM]

Originally Posted By: Gokhan
Originally Posted By: Hokiefyd
Is it possible that it had sheared down in Gokham's engine (say to 7.5 cSt), and had already started to thicken back up due to oxidation by the time it was UOA'd?

I would somewhat doubt that. We're talking about a high-quality modern fully synthetic oil here and I think my engine is fairly easy on the oil.

Also, most other posters are talking about the SM variety, which is completely different than the SN variety, the latter being significantly superior, with much better, less-shearing VIIs.



Our experience in many cars with the 0W20 SN TGMO is no different than with the SM version. And, after comparing the specs of the two, to say that the SN variety is "significantly superior, with much better, less shearing VIIs" is not only gross exaggeration, but unsubstantiated opinion since no one really knows WHAT VII's are being used. That information is proprietary with all blenders.

It's a very good oil, lake most of the Japanese MFR spec'd oils.

 

[Gokhan]

For any given oil label, its SN variety is always significantly superior to its SM variety because it uses the SN additive pack instead of the SM additive pack. SN additive packs are simply significantly improved over the SM additive packs.

Regarding VIIs, no, I don't really know, but they've been constantly improving and my impression has been that they've been using higher-quality VIIs with SN oils to meet more strict cleaning and sludge specs, as bad VIIs shear and therefore leave deposits behind.

 

[Hokiefyd]

Originally Posted By: Gokhan
Originally Posted By: Hokiefyd
Is it possible that it had sheared down in Gokham's engine (say to 7.5 cSt), and had already started to thicken back up due to oxidation by the time it was UOA'd?

I would somewhat doubt that. We're talking about a high-quality modern fully synthetic oil here and I think my engine is fairly easy on the oil.


Okay, so it's possible. You don't have a data point at, say, 2,500 miles. The starting viscosity is about 8.5 cSt for this oil at 100 deg C. Yours has thickened. And even there, there is going to be some lab variability. The same lab has not tested a virgin sample from YOUR bottle and YOUR actual sample to get an apples-to-apples measurement of viscosity.

Combine that with the fact that there's both sodium AND antifreeze in your sample, and even you question the sampling procedure...you drained it into a tin can before sending it to the lab.

In other words, I think there's little one can conclude from this.

 

[Hokiefyd]

Another thing to add: the flash point on the TGMO 0W-20 was 380, lower than that of the conventional Pennzoil 5W-20 previously used. There's a "TRace" of fuel reported by Blackstone on this sample. It's also possible that there's a smidge of fuel dilution into this oil, which typically lowers its viscosity and flash point from what I've seen before. If yours is sitting at a relatively high 9.0 cSt, any of the following could be true:

1) It started out higher than the 8.5 cSt we've seen reported before.
2) It's thickened to at least 9.0 cSt (not counting any fuel dilution).
3) Blackstone's number is not accurate.

I say it again: there seems to be so much going on here, so many variables, that few conclusions could be drawn from looking at any single metric.

 

[Gokhan]

Well, I wouldn't take the 8.5 cSt in the VOA posted here a while ago canonically. It was from a different lab and in the past TGMO 0W-20 was reported to have anywhere between 8.5 - 9.5 cSt. Batch-to-batch variations, formulation changes, etc. are also possible.

There is a possibility of antifreeze in the oil (deduced by Blackstone solely from the sodium). Trace for fuel dilution means it was negligible. My sample was only about 80% of the bottle and perhaps that wasn't enough for an accurate flash-point test, which requires a lot of sample.

Next time, I will try to sample it directly into the Blackstone plastic bottle so that we can be sure about the sodium and chromium. There is a possibility that my rubbing of the can with soap loosened the chromium plating on it and mixed it with sodium from the soap, which then came off when it made contact with the hot oil with various surface-fighting additives in it. We'll find out next time.