2023 Subaru WRX - 5567kms on Penn Plat 0W-20 SP (13986kms ODO)

[I_Hate_CVTs]

Hi Folks, latest UOA on the new WRX. This oil was used over the early winter, so lots of cold starts and short trips. Not comfortable with the viscosity and glad I dumped it early. I have 5W-30 Penn Ultra Plat in there now and will update when I dump that in the spring.

PQI is higher than previous interval? Thoughts?

Also having trouble understanding Oxidation, open to lessons.

 

[himemsys]

Fuel dilution is staying fairly consistent despite the winter run. Oxidation is more meaningful if you know the starting value (determined by virgin oil analysis). I'm guessing the Pennzoil is around 5. Oxidation is a measure of the oil breaking down. Oil Analyzers says normal if virgin value+17. So if yours went up 11-5=6, then oil life has not been exceeded.

Given this is a new vehicle, we're seeing normal wear-in results as they drop with mileage. Most noticeable with Cu, Fe and Si. All are dropping nicely and should reach normal levels within 2-3 more oil changes.

Viscosity is staying nicely in-grade considering the ~3% fuel dilution. With the PUP 5W30 you put in, keep in mind it starts off fairly low (9.9ish cSt) so it could still drop into 20 grade territory and it'd be normal.

I think this report looks really good.

 

[I_Hate_CVTs]

Fuel dilution is staying fairly consistent despite the winter run. Oxidation is more meaningful if you know the starting value (determined by virgin oil analysis). I'm guessing the Pennzoil is around 5. Oxidation is a measure of the oil breaking down. Oil Analyzers says normal if virgin value+17. So if yours went up 11-5=6, then oil life has not been exceeded.

Given this is a new vehicle, we're seeing normal wear-in results as they drop with mileage. Most noticeable with Cu, Fe and Si. All are dropping nicely and should reach normal levels within 2-3 more oil changes.

Viscosity is staying nicely in-grade considering the ~3% fuel dilution. With the PUP 5W30 you put in, keep in mind it starts off fairly low (9.9ish cSt) so it could still drop into 20 grade territory and it'd be normal.

I think this report looks really good.

Thanks for your thoughts! It's fun watching a new engine break in.

 

[I_Hate_CVTs]

Fuel dilution is staying fairly consistent despite the winter run. Oxidation is more meaningful if you know the starting value (determined by virgin oil analysis). I'm guessing the Pennzoil is around 5. Oxidation is a measure of the oil breaking down. Oil Analyzers says normal if virgin value+17. So if yours went up 11-5=6, then oil life has not been exceeded.

Viscosity is staying nicely in-grade considering the ~3% fuel dilution. With the PUP 5W30 you put in, keep in mind it starts off fairly low (9.9ish cSt) so it could still drop into 20 grade territory and it'd be normal.

I almost forgot... I did happen to do a VOA on the oil on this exact jug of oil before it went into the car. It is here: https://bobistheoilguy.com/forums/threads/voa-pennzoil-platinum-0w-20-sp.376872/

Oxidation was 6 and viscosity was 8.72 cST. So your math and guesswork on the Oxidation is very close. And over the interval with fuel looks like the oil dropped almost 1 cST over the course of about 5500kms.

I also forgot to get TBN tested for this UOA because this would have been a good comparison, but it's expensive to do so it is what it is.

 

[twX]

PQI is a measure of how much ferrous iron is in the oil. It's different than the spectrographic iron measurement in that it also detects larger particles. So compared to your last UOA, you have less small iron particles in the oil, but more larger ones.

The particles measured by PQI are large enough to be filtered, so they're more indicative of recent wear, whereas the iron ppm relates more to wear over the whole OCI. Higher PQI can be caused by less efficient filtration, which is probably why they label it as a "cleanliness" measurement. Have you changed filter models between the OCIs? Some aftermarket filters may bypass frequently on these engines, which would increase the number of large particles in circulation.

The higher PQI could just be because the oil sample was taken more recently after a high-wear event (cold start, short tripping, WOT), and the larger particles haven't had as much time to get filtered out before the sample was taken.

 

[I_Hate_CVTs]

PQI is a measure of how much ferrous iron is in the oil. It's different than the spectrographic iron measurement in that it also detects larger particles. So compared to your last UOA, you have less small iron particles in the oil, but more larger ones.

The particles measured by PQI are large enough to be filtered, so they're more indicative of recent wear, whereas the iron ppm relates more to wear over the whole OCI. Higher PQI can be caused by less efficient filtration, which is probably why they label it as a "cleanliness" measurement. Have you changed filter models between the OCIs? Some aftermarket filters may bypass frequently on these engines, which would increase the number of large particles in circulation.

The higher PQI could just be because the oil sample was taken more recently after a high-wear event (cold start, short tripping, WOT), and the larger particles haven't had as much time to get filtered out before the sample was taken.

Very interesting. Filter type has been the same since the beginning, black can Tokyo Roki from dealer. Your theory fits lots of cold starts, thick oil = lots of bypass.

Maybe also there are much better oil choices for this engine than Penn Plat 0W-20.

I also did hoon it a bit before the oil was dumped

 

[twX]

Oxidation was 6 and viscosity was 8.72 cST. So your math and guesswork on the Oxidation is very close. And over the interval with fuel looks like the oil dropped almost 1 cST over the course of about 5500kms.

With 3.4% fuel dilution, the oil would be expected to thin from 8.72 cST to around 8.0 cST. The measured 7.8 cST is only a bit lower than this, indicating that the oil is not shear-thinning much. This is to be expected with PP or PUP as they're quite shear-stable.

So, if viscosity concerns are holding you back from doing longer OCIs, I wouldn't worry about that, especially with the 5W-30. The fuel dilution won't continue to increase, and the oil won't shear thin much more on a longer OCI. A 6k km OCI isn't unreasonable for purely winter driving, but 10k through the warmer months would be completely fine, especially with PUP. If you're putting on 2k per month, you're nowhere close to the severe service short-tripping category.

 

[twX]

Very interesting. Filter type has been the same since the beginning, black can Tokyo Roki from dealer. Your theory fits lots of cold starts, thick oil = lots of bypass.

I also did hoon it a bit before the oil was dumped

The OEM filter shouldn't really bypass at all, so it's probably more that there's just been more recent wear from the hooning and such.

What does a UOA from this lab cost? I was going to use OAI in Edmonton for a UOA on my WRX, but I like the idea of getting some PQI tests to see how my PurolatorOne is filtering.

 

[I_Hate_CVTs]

With 3.4% fuel dilution, the oil would be expected to thin from 8.72 cST to around 8.0 cST. The measured 7.8 cST is only a bit lower than this, indicating that the oil is not shear-thinning much. This is to be expected with PP or PUP as they're quite shear-stable.

So, if viscosity concerns are holding you back from doing longer OCIs, I wouldn't worry about that, especially with the 5W-30. The fuel dilution won't continue to increase, and the oil won't shear thin much more on a longer OCI. A 6k km OCI isn't unreasonable for purely winter driving, but 10k through the warmer months would be completely fine, especially with PUP. If you're putting on 2k per month, you're nowhere close to the severe service short-tripping category.

Thanks for your thoughts. I agree with you on the different intervals summer vs winter.

The OEM filter shouldn't really bypass at all, so it's probably more that there's just been more recent wear from the hooning and such.

What does a UOA from this lab cost? I was going to use OAI in Edmonton for a UOA on my WRX, but I like the idea of getting some PQI tests to see how my PurolatorOne is filtering.

The first bunch cost $33 + tax each, but the last couple I bought were about $40 + tax each. Nothing escapes money-print induced inflation I guess.

I get the kits from the local CAT dealer, the part number is SOSOIL, comes with a bottle and plastic envelope etc. Return shipping is included in the deal, print your own label on Crappy Post using their return label code. PQI included in the standard analysis. TBN and TAN are not. My experience was that it was about $60 bucks to get TBN and TAN done, so I didn't do it again lol.

EDIT: I forgot to mention that I write on the return form and specifically ask for Fuel Dilution via GC. Don't know if they do it standard or not, but I have not incurred extra cost in asking.

What year is your WRX and what Purolator are you using?

 

[twX]

Okay, seems like it'll be about the same cost as OAI after paying for the shipping.

What year is your WRX and what Purolator are you using?

It's a 2015 and I'm using the PL14615. The same model should work for your car. It's got the proper bypass setting and should be more efficient than the OEM filter. They're around $14 on Amazon.

 

[fantastic]

Everything looks good on this report including the visc. What's interesting is that you had the same ferrous metal wear amount in 13k+ kms as your 1700 kms break-in wow! Goes to show how much wear debris happens in the beginning. Thanks for sharing.

 

[Fa24wrx]

Have you tested the Used PUP 5W30 yet?

 

[I_Hate_CVTs]

Have you tested the Used PUP 5W30 yet?

Nope, haven't dropped it yet. I'm almost at 5000kms, and will drop it at 6000 or shortly after, so next month. Definitely will send it off for analysis though and post.

I can say that running that oil, the engine is nice and quiet, does not feel harsh when you give it the beans as compared to the 0W-20 Penn Platinum I had in there.

I'd like to try the Mobil 1 ESP 5W-30, does anyone know if the new SP formulation has moly in it?

 

[I_Hate_CVTs]

Have you tested the Used PUP 5W30 yet?

What are you running in yours?

 

[Fa24wrx]

What are you running in yours?

Currently 0w20 PUP but trying to figure out which 5w30 to switch to. Leaning Valvoline EP or PUP