Used Oil Analysis - 30k to 40k

Yes, the OP's engine is fine but the Mobil 1 0W20 did shear about 20% which is a lot for a 0W20 synthetic oil with just a "trace" of fuel being shown. This is "The Critics" point about Blackstones "open cup" testing method for fuel, although we have never seen this on our comparative testing of the same oil sample with multiple labs.
Always a first time for everything !

Amsoil is a great oil and we use it in several vehicles, but not the Prius. It really is too heavy and is very close with it's 2.8 HTHS to being a 30 weight oil. The specs of the Amsoil 0W20 are KV 100C 8.7 cST compared to Toyota's 0w20 ( made by XOM ) KV 100C 8.54cST and Amsoils KV 40C 47.3 cST compared the Toyota's KV 40c
37.38 cst. Also,the VI of Amsoils 0W20 is a rather paltry 166 compared to Toyota's VI 0f 216. Amsoils HTHS is 2.8 compared to Toyota's 2.6 which is spot on for a 0W20 oil.

What this all means is the Toyota 0W20 synthtic oil is over 35% lighter at 0C ( 32F ) and over 25% at room temperature which is much more desirable for typical start-up temperatures and the frequent start/stops of the Prius ICE. At the moment, it is the lightest 0W20 readily available ( at your Toyota dealer ) and priced very competitively.

The 2.6 TBN is not really low for the OP's use. It is low when it get's to 1.0 and since TBN reducation is not linear ( it drops quickly in the first few thousand miles and then levels off ) there was more use available in the oil.

Getting a TAN and Particle Count analysis make the oil analysis much more meaningful in determinng it's condition and degree of extended use.

UOA'S of the Toyota 0W20 have indcated it is capable of 10K miles
depending on the application and use. It's a great oil !

 

I should have also pointed out the fact that the Toyota 0W20 Synthetic oil is substantially lighter than the Mobil 1 0W20 also
and is again the better choice for the Prius application.

 

I am not an oil expert so I have a couple of questions about this discussion:

Are you guys saying that the lighter an oil is the better? If so will you be using 0W10 or 0W5 if/when they become available?

I understand that lighter oils are better at startup with a cold engine as well as for mileage, but isn't there a trade off at the other end (i.e. 100 degrees C.)? Wouldn't a synthetic rated at 20 or even 30 at normal operating temperatures have an advantage at those temperatures? Would someone who mostly uses his car for longer trips be better off with a slightly heavier oil, perhaps Mobil 1 0W20 vice Toyota 0W20?

I don't really care about the slight advantage in fuel economy, I am thinking of what would be best for the engine.

I have been using Mobil 1 0W20 in this Prius since the first oil change at 1500 miles in Sept of 2009. I couldn't get the Toyota oil in this area at that time. Do you think there would be any point in changing to the Toyota branded product now? I have heard that it is best to stick to the same brand of oil once you start using it, any truth to that?

 

Yes, the lighter Toyota 0W20 is designed to be as light a possible for use in the Prius, especially with it's ICE's frequent start stops.
The Toyota 0W20 synthetic oil is 35% lighter than Mobil 1 0W20 at 0C ( 32F ) and 25% lighter at room temperature. ( ALL oils are too thick at start up......with over 80% of wear occuring at start up, the lighter the better )

Under normal driving conditions, where 0W20 is recommended by the MFR, and in this case it is by Toyota, there is absolutely no need to consider a 30 weight oil. Heavier oils are only necessary in extreme conditions such as tracking a car, or trailer towing and especially when specified by the MFR. In some cases, worn and oil burning engines also may require a thicker/heavier oil. There is no advantage to using an oil that is heavier/thicker than necessary. Trips at 70-80 MPH do not require any other oil than the 0W20 specified by Toyota,
Now.....if you're going to be blasting down the autobahn at 140-150
MPH that's a different story. ( Doubt anyone will be able to do this with the Prius' top speed of 103 MPH )

There is absolutely no probem with switching from one oil to another.
Synthetic to synthetic, dino to synthetic, synthetic to dino. In the case of the Prius however, keep in mind SYNTHETIC oil is what's recommended. It is preferable to run one brand continuously, but not
absolutely necessary. Now, if you're going to do a UOA, it is suggested that you run the oil for at least 2 OCI's.

Like you, we care more about engine protection than economy. Considering that unless you're doing constant and continuous freeway or highway driving, the Prius ICE will rarely reach full operating temperature. In stop and go driving, it will most likely never reach full operating temperature. In fact. the oil in the Prius ICE will most likely NEVER see 100 degrees C. In normal warm up, in both the Prius ICE and other non hybrid applications, the oil temp lags behind the coolant temp by 20 degrees or more.

Towing, going up loooooong steep hills or mountains, and tracking will certainly raise both coolant and oi temps, but those are exceptions to the norm. And, when oil temp does rise, it quickly cools when the heavy load conditions end.

Changing from Mobil 1 to Toyota's exellent 0W20 Oil is strictly up to you, but all FACTS point to it being a much better oil for use in the Prius application.

Finally, we will only use a "lighter" oil such as 0W10 when specifically recommended by the MFR. They know more about the engines they design and build than we do. ( FYI, Honda is working on a 0W10 oil.)

 

Yes, the lighter Toyota 0W20 is designed to be as light a possible for use in the Prius, especially with it's ICE's frequent start stops.
The Toyota 0W20 synthetic oil is 35% lighter than Mobil 1 0W20 at 0C ( 32F ) and 25% lighter at room temperature. ( ALL oils are too thick at start up......with over 80% of wear occuring at start up, the lighter the better )

Under normal driving conditions, where 0W20 is recommended by the MFR, and in this case it is by Toyota, there is absolutely no need to consider a 30 weight oil. Heavier oils are only necessary in extreme conditions such as tracking a car, or trailer towing and especially when specified by the MFR. In some cases, worn and oil burning engines also may require a thicker/heavier oil. There is no advantage to using an oil that is heavier/thicker than necessary. Trips at 70-80 MPH do not require any other oil than the 0W20 specified by Toyota,
Now.....if you're going to be blasting down the autobahn at 140-150
MPH that's a different story. ( Doubt anyone will be able to do this with the Prius' top speed of 103 MPH )

There is absolutely no probem with switching from one oil to another.
Synthetic to synthetic, dino to synthetic, synthetic to dino. In the case of the Prius however, keep in mind SYNTHETIC oil is what's recommended. It is preferable to run one brand continuously, but not
absolutely necessary. Now, if you're going to do a UOA, it is suggested that you run the oil for at least 2 OCI's.

Like you, we care more about engine protection than economy. Considering that unless you're doing constant and continuous freeway or highway driving, the Prius ICE will rarely reach full operating temperature. In stop and go driving, it will most likely never reach full operating temperature. In fact. the oil in the Prius ICE will most likely NEVER see 100 degrees C. In normal warm up, in both the Prius ICE and other non hybrid applications, the oil temp lags behind the coolant temp by 20 degrees or more.

Towing, going up loooooong steep hills or mountains, and tracking will certainly raise both coolant and oi temps, but those are exceptions to the norm. And, when oil temp does rise, it quickly cools when the heavy load conditions end.

Changing from Mobil 1 to Toyota's exellent 0W20 Oil is strictly up to you, but all FACTS point to it being a much better oil for use in the Prius application.

Finally, we will only use a "lighter" oil such as 0W10 when specifically recommended by the MFR. They know more about the engines they design and build than we do. ( FYI, Honda is working on a 0W10 oil.)

 

What's the general consensus of Honda 0W20 vs. Toyota 0W20 for 3-4 cylinder hybrid (i.e. autostop) motors?

 

Honda has both a synthetic blend 0w-20 and a full synthetic 0w-20. Their oils are now made by ConocoPhillips.

The Toyota 0W20 is the only 0W20 on the market that with the super-low 40C viscosity and the super high Viscosity Index. It is truly a unique product that is unmatched by any other 0W20.

 

Both are good oils, but the Toyota 0W20 is lighter with a higher viscosity making it the thinnest easily available and cost effective
0W20 oil on the market.

 

Here is mine not sure of what to take of the 5W30 which I hope a mistake ... I am hope Toyota put the right 0W20 oil

http://priuschat.com/attachments/uoa-090812_redact-pdf.42244/

 

Looks like you got the oil of the day, which was probably 5W-30. But you can't complain about the lack of wear, and 30-weight in summer isn't a terrible idea. Thanks for sharing.

 

well it was not the summer this oil lasted from November 2011 till NOW about 10 months!!!

 

Where do you got that Mobil 1 0W20 is so much worse than TGMO 0W20? Im not a pro but does this match this table at all? (Im not allowed to post a link so when you google for: toyotanation 0w20 recommended oil
you will find the table i mean.)

Im currently interested in the motor oil topic because i bought a prius hybrid III some months ago and had my first check at a toyota workshop. After that i found that i consistently have 1 liter higher usage of gasoline. I only drive short tracks, under 5 kilometers, so the motor doesnt get hot.

I wanted to make them fuel in the correct oil but they didnt want. Only want to give 0W20 next time for free... but when i really would need to use 1 liter more gasoline all the time it wouldnt make sense.

If your numbers are correct then i shouldnt use Mobil 1... where do you got the numbers from? And are there other good oils? What about the royal purple? I found a shop that offer royal purple 0W10 for the prius of 2010... so is this a good choice then? Royal purple has 0W5 oil too.

 

I tired to find the parameters of Toyota oil 0W20 in internet. No results. You say it has super low 40C viscosity - can you please advise where you get it from? thanks

 

The oil or the spec? The oil you can get from any Toyota dealership.

Is that Birmingham in Alabama or England, btw?