Not just Subaru.
The new 2024 Subaru Crosstrek calls for 0w-16.
- Thread starter Jeep_Riot
- Start date
- Status
- Joined
- Jun 3, 2021
- Messages
- 832
What's a WAG?
As I noted above.
Wild Approximate
Guess
This study is decades old. Modern oils with novel base stock and add pack combinations would no doubt yield better results.
I would not expect a 2005 0W10 motor oil to be anything like a 2022 GF-6B 0W8, especially considering that HPL is at the highest end of the spectrum in capabilities.
Respectfully, this study, claiming that start up wear, or warm up wear, is not influenced by viscosity is now dubious and outdated IMV.
where is seafoam and Lucas oil at?
Why would you think start-up and warm-up wear not being influenced by viscosiy is now "dubious" when the study showed it wasn't back then? Viscosiy is viscosity, regardless of the add pack. You don't think the same correlations would happen with modern oils? If so, why not. It serms temperature induced, regardless of oil viscosity or formulation.
The same testing would have to be conducted today, but that study concluded that the ring and cylinder wear rate went up as the oil and coolant temperature degreased (ref post 69), and that phenomenon was seen regardless of what oil was used. Same held true with the wear rate increasing with higher loads and RPM - but no surprise there as any engine beat hard at higher HP levels and higher RPM will wear faster (other factors constant) compared to not using it that way.
Last edited:
Oils are now better designed. It is stated that very thin oils are especially reliant on clever designed to achieve adequate protection.
Any arcane 2005 10W20 motor oil with the same composition as a common fleet tested 15W40 is going to be a weak sauce by today's standards.
We shall see in 2 or 3 years how my engine holds up at 200k miles on HPL PP 0W8.
I doubt there will be too much wear overall, let alone start up or warm up wear.
Updated testing would be welcome, especially that devoid of confirmation bias.
Edit: removal of inevitably inflammatory terminology.
Last edited:
Think you are going off on a tangent and talking about wear after warm-up an running at normal operating temperature. One part of the study was showing wear rates during start-up and warm-up, and I'm betting the same correlation would be seen today with modern oils ... ie, that wear would correlate to oil and coolant temps during engine warm-up, not really dependant on the viscosity. Thankfully, the time an engine is warming up is typically much lower than the time it spends at full operating temps ... unless of course the vehicle is a major short tripper.
Been plenty of studies done showing that with different oil viscosities with the same add pack, that more wear is seen with lower viscosity oil. Viscosity (the "film thickness") will always be the main mitigating factor that controls wear, followed by the AF/AW add pack (the "film strength"). There is start-up/warm-up wear, and then there is wear at operating temps, and beyond. They don't seem to be very connected because the warm-up wear isn't very dependant on viscosity (same add pack), whereas the operating temp wear is more dependant on viscosity (again add pack is the same).
At 200K use walnut oil for your top off's.
Then at 300K, nothing but hero shots of clarified butter
Do they have some special oil pump in them to keep the oil pressure up when the oil gets hot?
delete.
If it specifies 0W-16 then the oil pump better be designed to adequately pump it and provide decent lubrication volume. Oil pressure doesn't really matter as much as getting the proper oil volume to all components - the positive displacement oil pump ensures adequate volume, even if the oil is very hot and the pressure gets lower. Only components that may be oil pressure sensitivity would be VVT related.
Even just pushing it through the oil filter requires pressure, could be 30 psi.
Not that much when warm/hot, but maybe possible with super cold oil and high RPM. But in that case, either the filter bypass would kick in, and/or the pump would hit pressure relief first and cut back flow output.
With fully hot oil the pressure drop across the oil filter would probably only be around 5 to 7 PSI. Good oil filters are not very flow restrictive. The typical oil filter is typically only 1/15th as flow restrictive as the engine oiling system. For example, If the pump is puttung out 80 PSI, 5 of that is dropoing across the oil filter, and the remaining 75 PSI is dropping across the oiling system down stream of the filter. 5 PSI is 1/15th of 75 PSI.
Last edited:
- Joined
- Oct 21, 2015
- Messages
- 233
I’m giving the average BITOGer a run for their money eh
I was thinking of a different word for what you’re doing, as are others.
To think otherwise shows litttle knowledge of bearing lubrication.
The "Bearing Characteristic Number ) is defined as: viscosity x rpm/load.
There is a "critical point" in a given application whereas if the number becomes lower the bearing will become unstable and fail.
Notice that increasing viscosidy increases the "bearing characteristic number" that's Mechanical Engineering 101 folks.
How many miles do you have on it? Oil usage?. Our '17 used no oil with the 0w20 but its was vary clanky when hot. Like "I wouldn't buy that car, the engine is shot" clanky. Our new 2023 was dead quiet then it started knocking after about 3000 miles in service. It uses about a quart over the 6k mi. OCI. I don't know what's up with these boxer engines, the last well running one was the great 2.2 in a 1996 Impreza wagon.
I wouldn't go near a 16. I top off with 10W30 and the engine is much quieter with a bit of that in there.
But the 2.0 FB don't like 5W30 - they wont run well. Sluggish.
Genuine Subaru 0W20 made by Idemitsu in Indiana is a good oil. It runs clean, the engine makes good power on it and is very responsive. Better than any other major brand - save maybe the old M1 EP 0w20. The new formula is no longer a majority group IV - a true synthetic.
Stay the course.
- Status
Similar threads
