Valvoline R&P 5w30- 3,017 mi- 2022 Subaru Wrx UOA

[Fa24wrx]

This is my first ever UOA. I see minor Fuel Dilution at 1.6% which is what dropped viscosity to 8.9. Any other input would be great. I'm currently on a fresh oil change with the same fluid for fall/winter but will probably switch to Mobil 1 5w30 ESP by next spring/summer.

TBN looked really good after 3k miles but I worry about extending interval with the viscosity drop. Although, I think I read viscosity wouldn't keep dropping? Is that true?

 

[buster]

Looks really good. Viscosity dropped, but that is not surprising in a RC 5w30 oil. Probably the one thing I'm not thrilled about so far based on UOA's I've seen. Wear is very low, TBN is strong. No oxidation at all based on virgin/used numbers. I'd stick with it.

 

[Fa24wrx]

Looks really good. Viscosity dropped but that is not surprising in a RC 5w30 oil. Wear is very low, TBN is strong. No oxidation at all based on virgin/used numbers. I'd stick with it.

Would you be OK with that viscosity considering ny temps max at around 221f for a few seconds with short highway pulls to pass traffic?

 

[buster]

Would you be OK with that viscosity considering ny temps max at around 221f for a few seconds with short highway pulls to pass traffic?

Ideally I'd want it to remain in grade but based on the results I see there is no wear concern at all. They do make a 10w30 grade of this oil which should be more shear stable in theory (less VII), but it's not available yet.

Does this engine call for a 20 or 30 grade?

 

[Fa24wrx]

Ideally I'd want it to remain in grade but based on the results I see there is no wear concern at all. They do make a 10w30 grade of this oil which should be more shear stable in theory (less VII), but it's not available yet.

Does this engine call for a 20 or 30 grade?

Oem calls for 0w20. I think Aus has 10w30 but not here yet.

 

[Fa24wrx]

Ideally I'd want it to remain in grade but based on the results I see there is no wear concern at all. They do make a 10w30 grade of this oil which should be more shear stable in theory (less VII), but it's not available yet.

Does this engine call for a 20 or 30 grade?

One more question: would you stay at 3k mile OCI? I enjoy doing them and the cost isn't a burden.

 

[hitechrr]

Why not use 0w20. It will provide less friction. My new Toyota calls for 0W8 and my lab results look great. I use 0w20 in my gmc truck and my mazda6 and the lab results are good.

 

[buster]

One more question: would you stay at 3k mile OCI? I enjoy doing them and the cost isn't a burden.

I'd probably go to 5k based on your results but if you don't mind doing oil changes, sure. This oil has plenty of life left though.

They have a 5w20 R&P too.

Not sure what oil temps you're seeing, but it had no impact on the oil with oxidation spot on with virgin numbers.

 

[Fa24wrx]

Why not use 0w20. It will provide less friction. My new Toyota calls for 0W8 and my lab results look great. I use 0w20 in my gmc truck and my mazda6 and the lab results are good.

The manual says 0w20 but thicker viscosity may be needed in hotter climates. I live in the southern USA where we get 100f ambient and 220-230f oil temps regularly on highway driving or spirited drives. Plus, Japan calls for 5w30 for this exact car/motor.

 

[Fa24wrx]

I'd probably go to 5k based on your results but if you don't mind doing oil changes, sure. This oil has plenty of life left though.

They have a 5w20 R&P too.

Not sure what oil temps you're seeing, but it had no impact on the oil with oxidation spot on with virgin numbers.

With spirited driving, 220-230f isn't uncommon

 

[fantastic]

Welcome to the UOA forum. If your WRX calls for 0w-20 & you're using a 5w-30 instead it should allow some viscosity drop, from fuel, but still have film thickness to protect the engine. At almost 2% I'd stick w/5w-30 and run it out to 5k at least.

 

[Fa24wrx]

Welcome to the UOA forum. If your WRX calls for 0w-20 & you're using a 5w-30 instead it should allow some viscosity drop, from fuel, but still have film thickness to protect the engine. At almost 2% I'd stick w/5w-30 and run it out to 5k at least.

That was something I thought about too. Since it calls for 0w20, this ended up at the upper end of 20 after dilution.

If i end up tuning, I'll switch to a more stable oil

 

[kschachn]

Why not use 0w20. It will provide less friction. My new Toyota calls for 0W8 and my lab results look great. I use 0w20 in my gmc truck and my mazda6 and the lab results are good.

Because of fuel dilution and subsequent loss of film thickness. Friction is not an issue.

 

[Fa24wrx]

Welcome to the UOA forum. If your WRX calls for 0w-20 & you're using a 5w-30 instead it should allow some viscosity drop, from fuel, but still have film thickness to protect the engine. At almost 2% I'd stick w/5w-30 and run it out to 5k at least.

Another question, why did they want to know sump size for next one?

 

[fantastic]

Another question, why did they want to know sump size for next one?

Sump size plays a role in gauging how long they can recommend an interval for. This is my assumption. You wouldn't want to run a 3.5 qt system as far as a 6 qt system on some vehicles. More oil can potentially handle more contaminates etc. consequently lasting longer.

 

[Fa24wrx]

Sump size plays a role in gauging how long they can recommend an interval for. This is my assumption. You wouldn't want to run a 3.5 qt system as far as a 6 qt system on some vehicles. More oil can potentially handle more contaminates etc. consequently lasting longer.

Gotcha!

 

[Sandstorm]

I think there was some fuel dilution in the VOA that I saw. Overall, the results look great.

 

[Fa24wrx]

I think there was some fuel dilution in the VOA that I saw. Overall, the results look great.

You're right. I looked at that thread. It was 1.3%. Would it be accurate to deduce less than 0.5% from my vehicle making it go from 1.3 to 1.6%? I realize there is some error wiggle room so maybe that isn't how it works.

 

[RDY4WAR]

Factoring out the 1.6% fuel dilution, the resulting viscosity is 9.32 cSt. (assuming the KV100 is exactly 8.90 and fuel exactly 1.6%, could be rounded figures) The VOA showed a KV100 of 10.7 so the oil sheared -1.38 cSt. (-12.9%) It's still in grade but barely. With the fuel, it's obviously out of grade.

Otherwise, the report looks good. Given that this oil is designed to clean rather well, I would keep the intervals short for the next couple runs. Check the filter for carbonaceous material to base your OCIs going forward.

 

[Fa24wrx]

Factoring out the 1.6% fuel dilution, the resulting viscosity is 9.32 cSt. (assuming the KV100 is exactly 8.90 and fuel exactly 1.6%, could be rounded figures) The VOA showed a KV100 of 10.7 so the oil sheared -1.38 cSt. (-12.9%) It's still in grade but barely. With the fuel, it's obviously out of grade.

Otherwise, the report looks good. Given that this oil is designed to clean rather well, I would keep the intervals short for the next couple runs. Check the filter for carbonaceous material to base your OCIs going forward.

The car is relatively new. The filter was clear on the last OCI with this oil.