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Time to switch oils in 2007 Subaru EJ25 turbo with 150k?
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The 0w40 Castrol is a good fit for these engines and is easy to get and not too expensive. No need to go boutique with these engines, the Castrol Euro oils are very good oils in their own right.
The Owner's Manual viscosity grade recommendations or any other specifications?
Poor OM always gets neglected on bitog.
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Headslap. Duh. Owners Manual never occurred to me.The Owner's Manual viscosity grade recommendations or any other specifications?
Poor OM always gets neglected on bitog.
OM: 5w30 SM “preferred.”. Also 10w30 and 10w40 if over 0 Fahrenheit. GL4. I never noticed severe duty section before: 30, 40, 10w50, 20w40, 20w50…SM or SL. Phew, the SL I’ve been using is OK, though no mention of 0w30, 0w40, or 5w40.
also no mention of SN, SN+, SP or any ACEA grades. Nor any mention of synthetic. My how times have changed.
retract headslap. OM guidance is not especially useful. OK, no 0w16, no 0w20, I get it. And I also get: USA 0w30 might also not be appropriate, but the Castrol Euro Edge 0w30 is thicker than any USA 5w30.
Winter rating is irrelevant in terms of selection except for the expected starting temperature. Other than that it can be ignored in any owner's manual recommendation.
No engine is harmed by an oil with a higher HT/HS. It can however be harmed by an oil with too low of an HT/HS. As you note I would not go to a lower grade than what the manual recommends. Film thickness prevents wear, not harms. Just because a manual does not mention a grade higher than -30 isn't particularly relevant.
There in Texas a 40-grade with the corresponding HT/HS of 3.5 or so is entirely reasonable.
No engine is harmed by an oil with a higher HT/HS. It can however be harmed by an oil with too low of an HT/HS. As you note I would not go to a lower grade than what the manual recommends. Film thickness prevents wear, not harms. Just because a manual does not mention a grade higher than -30 isn't particularly relevant.
There in Texas a 40-grade with the corresponding HT/HS of 3.5 or so is entirely reasonable.
I’m a bit of a thickie, but only moderately so. The Castrol Euro Edge 0w30 (son or grandson of “German Castrol”) hit my sweet spot: 12.1cst, HTHS 3.5. a more modern version may be the ticket. There is a newer Castrol Euro Edge 5w30 which might do, but I thought some of the euro crowd ( like @edyvw ) didn’t like it as much as the 0w30. In fact I thought their pecking order among the Castrol Euro’s was 0w30, then 0w40, then 5w30, then 5w40…I could be misrepresenting them. And they could say why in the world am I quoting them for a Subaru? But my whole intro into this oil rabbit hole started with Turbo Subaru owners bashing M1, and anything lesser, loving the old Rotella 5w40 for their catless buzzbombs, with a few praising the original German Castrol as well. I’ve been using the euro 0w30 for 7 years??? Well, last 2 fills were mixes: 0w30 and 0w40 kissing cousins…only because my source of 0w30 ran out. It will be interesting if the upcoming mixed UOA lives up to the straight 0w30 UOA’s (latest in 2020).
There are changes.
Castrol Edge 0W30 stayed the same.
0W40 is changed to API SP, but not available still in the US.
5W40 got thinner couple years ago but it is still GrIII.
5W30 stayed same, and it is GrIII.
Main difference is that 0W30/40 have good amount of PAO. 0W30 stayed around 50%, while new SP 0W40 is more around 25%.
So this prompted me to look at Castrol’s PDS pages. it now appears to me that the 5w30 A3B4 has been available much longer than I thought (PDS dated 2014?). Also, the 0w-40 A3B4 appears to have been replaced by a 0w-40 PA (Which is still A3B4, and still only SN As of late 2022).
will the new 0w40 still be “PA“ ( whatever that means)? Obviously I haven’t been keeping up with current events.
I was under the impression PAO was inherently superior to Grplll, hence my loyalty to the Edge Euro 0w30, but recent discussions seem to indicate while it still might be…PAO is most useful for ultra low temp “xw” purposes…which aren’t that relevant to me (in Texas).
PAO is better, but it is more nuanced than that. Each base stock has its advantages and disadvantages. PAO oils generally have higher HTHS. Motul managed in GEN2 oils to get some really good HTHS out of Group III oils.
You don’t need 0W in TX. Heck, I don’t need it in CO. But that is not the reason why I am using it.
Here is UOA of Castrol 0W30 (right column) and 0W40 (left). 0W40 also had some serious track mileage at 100f+ temperature at 5,000ft altitude and sessions as long as 45-60min.
0W30 was ran in winter, with numerous cold starts at ski resort, sometimes as low as -30.
Maybe your point was 0w30 vs 0w40…meh, what’s the difference? But I like the lower KV100 of the 0w30, and related lower kv40. Still, other than CST, they performed pretty much the same…and I’m hoping my current mix of the two would also be in the same ballpark.
but I thought since I was now all out of Castrol Euro, maybe it was time to look “forward,” not backward…of course ”newer” is not always “better,” and A3B4 Castrol has done well so far. Sure, A3B4 oils with >1.0 SA might be a bit dated, but are you still using them? Those UOA’s were from 2021. Though again, they looked quite good to me.
By the time my EJ turbo got to 90k miles the consumption was up to nearly 2 quarts in 6k mile intervals. I switched to Edge 10W-40 and would use 0W-40 for top ups to thin it out a bit during winter. That plan got me to over 190k with less than a quart consumption at just over 5k intervals before the car was totaled and I sold it.
The car rarely saw any oil that had less than an HTHS of 3.5 after about 82k miles. I believe I ran it only once after that point because I was getting work done at the dealer. The only power mod was a Cobb AP running an OTS tune and I didn’t install that until the 110k mile mark.
You haven’t mentioned consumption but I’d still stick to a thicker oil regardless.
The car rarely saw any oil that had less than an HTHS of 3.5 after about 82k miles. I believe I ran it only once after that point because I was getting work done at the dealer. The only power mod was a Cobb AP running an OTS tune and I didn’t install that until the 110k mile mark.
You haven’t mentioned consumption but I’d still stick to a thicker oil regardless.
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Stop mixing oil grades!
Best bang for the buck, QSFS Euro 5w-40.
Best bang for the buck, QSFS Euro 5w-40.
PAO is also still superior with oxidation resistance.
why?
Because the outcome is unpredictable. Add pack compatibility and results and final v@40 and V@100.
In VW’s I use VW504.00/507.00, low SAPS. In BMW, I use whatever is good. I have some Castrol 0W30 on the shelf, som 50qt of Motul X-Cess 5W40, some 20qt of Motul 5W40 300V, some Mobil1 0W40. Nit sure I will buy anything for BMW for some time
What about the upwards of 20 percent residual oil that was still in the engine? How the engine shears the oil? I am curious on the prediction angle. Are you an oil analyst?
I added 100k on a modified car, with the same engine as the OP, with an unpredictable outcome mixed oil.
KV@100 didn't matter to me since I knew it was thicker than the "preferred" grade and KV@40 didn't matter since straight 10W-x could be used down to -4º F.
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