2019 Subaru Ascent FA24, 7.1k, HPL PCMO 5w30

[SubieRubyRoo]

Numerous Subaru used oil analysis all showing low wear regardless of oil.

3% fuel dilution, 3k miles.

S

Thread '2023 Subaru Outback XT FA24F; Mobil 1 0w20 / 0w30 mix ; 3189mi'

Nov 13, 2025

Oil report for my new-to-me 2023 Outback, this was a 50/50 mix of ESP 0w20 and 0w30. The intent was to get a viscosity that would dilute/shear to into 20 grade instead of below like a lot of other oils have seemed to do over on the outback forums within 3k miles. The car is mostly used for kid hauling/grocery getting so not a ton of longer trips/highway miles. This oil was in service for approximately 4 months. This came out and straight ESP 0w30 went in, decided to stop trying to play backyard chemist. For the next interval, I feel confident in running it for a full 6 months or 6k miles...

• sac240
• Replies: 19
• Forum: Used Oil Analysis - Gasoline

• 

Buster, cmon now… it’s almost a stretch to take a 3k OCI (on any oil) and extrapolate that to say “the oils are the same” as OCIs that are more than twice the mileage. My other UOA was even longer mileage with much higher fuel (nearly 8%) and yet the wear rate captured in the oil was nearly identical.

I’m not saying low wear rates is not an inherent FA24 positive, as it may be, but I think it’s wishful thinking or bad advice to take such short data points on some oils and claim they’re equals when there are no comparable tests at distance. We know what the FA24 and HPL are doing at 7-10k+ from my used oil analysis; other oils we only know what they’re capable of at 3-5k max. That’s all I’m saying.

 

[buster]

Buster, cmon now… it’s almost a stretch to take a 3k OCI (on any oil) and extrapolate that to say “the oils are the same” as OCIs that are more than twice the mileage. My other UOA was even longer mileage with much higher fuel (nearly 8%) and yet the wear rate captured in the oil was nearly identical.

I’m not saying low wear rates is not an inherent FA24 positive, as it may be, but I think it’s wishful thinking or bad advice to take such short data points on some oils and claim they’re equals when there are no comparable tests at distance. We know what the FA24 and HPL are doing at 7-10k+ from my used oil analysis; other oils we only know what they’re capable of at 3-5k max. That’s all I’m saying.

It's a good report. Oil did it's job. I wasn't trying to compare them but most Subaru/Toyota engines show low wear regardless.

I'd be happy with your results.

 

[tired]

Considering the OEM recommends 20 grade, I don’t care one bit about ending viscosity at 8.7.

Besides, the oil cooler is on the top of the engine, right under the oil filter. Not sure why you’re so averse to oil running at 212* or above, especially an oil as robust as this?

Well we all know why the OEM recommends a 20 grade. It's not for engine longevity...

If you're ok with 7000 mile OCIs, and you're ok with the oil viscosity diluted out below a 30 grade, why not just run a VW 504/MB 229.5 oil off the shelf at Walmart?? What am I missing here?

 

[SubieRubyRoo]

Well we all know why the OEM recommends a 20 grade. It's not for engine longevity...

If you're ok with 7000 mile OCIs, and you're ok with the oil viscosity diluted out below a 30 grade, why not just run a VW 504/MB 229.5 oil off the shelf at Walmart?? What am I missing here?

You probably could do that if you wanted. However, I don’t for at least 2 main reasons:

1. OTS oils are not crafted with the best quality raw materials like @High Performance Lubricants are. With a decent amount of fuel in the oil, this greatly increases the risk of acid formation in the crankcase, especially over long OCIs & winter temp variations. This places a premium on oxidation prevention and base number retention, which HPL has clearly demonstrated. Nearly every other UOA we’ve seen on FA24s have TBNs below 2.5, indicating the oil is not useful much longer. See here:
https://en.oelcheck.com/wiki/acids-in-the-oil/

2. Because I want to support a company who’s repeatedly crafted bespoke oils all across our hobbies- from car oils to racing oils, gear oils, generator oils, SxS oils, even oils for my zero turn. Always the highest quality, always amazing customer service. Plus, if I have any questions I get to call and talk directly to somebody who will help.

So, small price premium or not, every oil I buy is from Dave Ward, because it’s obvious he cares about his customers. The price differential when using HPL products to their maximum abilities disappears once you get into multiple distances of your OCIs on OTS oils and include the duplicate filters you’d use along with the time you spend under the vehicle.

TL;DR:HPL provides value outside of the cost of their product. So I buy it exclusively and it makes me happy to support a business that values its customers.