The CCS, I'm sorry.
HPL SAE 40 PCMO
- Thread starter Hohn
- Start date
And if you really get down to it, pumpability is a binary. Either it will or it won't. Cranking is different.
I can answer this one at least. He wants higher viscosity. HTHS tops out at 3.6 on that line. Good for a racing oil, but if you wanted a racing oil, then just buy their racing oil. The Euro oils top out at 4. He is looking for 4.2 minimum HTHS. That's basically where wear hits the asymptote of little to no wear occurring per Leslie Rudnick's writings. He likes the PCMO line due to the value and it checking all the boxes he's looking for.
Is this car used on the track? ... I don't recall if that was mentioned. The HPL 10W-40 has a HTHS of 4.06 cP, that's some decent dynamic viscosity. HPL 10W-50 has a HTHS of 5.07 cP if someone want's to go wild, lol. 10W would in the best case scenario would be good for -25C (-13 F). Like mentioned earlier, most vehicle manufacturers that show a viscosity vs ambient temps chart will typically be more conservative than J300 specs. That's because each engine behaves differently to cold starts and not all engines may be able to safely cold start at the minimum W grade temps shown in J300. That's why the Yamaha OM shows much more conservative minimum temps for the viscosities listed.
Here's what I'm talking about - I put the J300 W section in there and annotated the differences. Yamaha won't push the engine to take the minimum J300 W grade temps ... maybe it mostly due to starter and battery capability, but could also be due to some lubrication concerns.
HPL doesn't show any CCS or MRV test data for their straight SAE 30 and SAE 40 grades. It would certainly be interesting to see where they would test at. Could be their straight 40 grade comes in equivalent to a 15W-40, or it could be a 20W-40 ... wouldn't know without actual test data. Even if it was basically a 20W-40 it would theoretical be good for -15C (5F) in the best case scenario.
No it is a commuter car.
He has expressed interest in the 50 grade HPL offerings...
I want to say that I read here or elsewhere that it being close to a 20W winter rating was hypothesized.
Right. That's why the MRV is the real startability limit where the OIL is the limit. CCS is the startability when the starter and battery are the limit.
By design, MRV is more stringent (5C colder) to assure that if the engine can crank the CCS, then it cannot be damaged by excess MRV viscosity.
But in the case of HPL oils, the MRV is far, far below J300 limit-- sometimes only 20% of the allowed limit. So even the "thick" HPL oils have superb pumpability at very cold temperatures, far better than the 15w or 20w (or the lack of a "w" at all!) would suggest.
Which is why so far the monograde SAE 40 has been much ado about nothing in terms of cold starting. Now a lot can change in 15 degrees and the effortless starts at 28F (this morning) don't mean 15F is cake walk. But it does mean that 20F is likely to be manageable and for a mostly garaged vehicle that is rarely to never starting with oil temps of 15F, the monograde becomes surprisingly viable.
I've been advocating for the SAE 40's cold viability based on the 15w-40 and a bit of faith in specs and calculations. But now that I've had it in and started at 28F or so more than once, I'm feeling like this whole exercise is far less risky than I initially suspected.
Even at 28F, the oil pressure is INSTANT. That's the payoff of the very low MRV relative to grade of these HPL PCEO formulations. GTL bases ftw.
I'm guessing based on early experience that the real world cranking difference between the 15W and the SAE 40 is about 10F. I expect the monograde at 25 cranks about like the 15w at 15F.
Now if you get caught out with the monograde in 5F or so temps, things could get sideways in a hurry. Your starter might decide it's had enough and eject because it's being asked to do a LOT of work pumping monograde at those temps.
The picture I can see emerging is that the monograde is quite viable year round here in Indiana but probably requires some minor "management" in the way that a 15w or less simply doesn't. If you have the 15w HPL or lower "w" in the pan, the oil is never the reason you won't start here in our area.
The monograde raises the risk of oil-related crankability from zero to something nonzero. It puts it on your radar when previous it was never an issue.
I'm not even convinced for myself that it's worth that tiny bit of management. But I'm curious, so I'm charging ahead with at least a 10k oci of the stuff just to see for myself.
I mean that viscosity is a two way street. I higher VI doesn't just thicken less when cold, it thins less when hot.It's a 40 grade, so when at 100C and 150C the kinematic viscosity and HTHS viscosity are thicker than any viscosity less than a 40 grade. Don't know what you mean in the bold part in your post.
The monograde gets around this by simply shifting the entire curve upward in viscosity. But it shifts the bottom end up much more than the top end.
That's why I think it likely a poor choice for racing, there's a pretty significant pump work penalty on this oil compared to a 0w-40 or likely even a 5w-50. I'm guessing most vehicles would show a 5hp or more detriment on the monograde.
So, IMO not a track oil. Thankfully, this is an accord and a track is far outside its domain.
My calculations/estimations suggest the monograde would test as a 15w by MRV, but likely a 20w or 25w by CCS.
ASTM D341 isn't really a perfect calculation though because it's based on equations developed around mineral oils with significant wax content.
Which is why I hypothesized that a GTL or PAO base oil was likely not as thick as the equations would suggest and that it might not be so scary in colder weather.
I honestly won't know any time soon, this recent blast to the upper 20s is likely my last cold weather until next winter, and even then we don't get far below 20F here with regularity.
But if I can run this year round here in south central Indiana-- then there's a good chance someone in Oklahoma or TN can run it quite successfully also. Maybe not. Maybe we'll learn.
So who in MN or ND is signing up to be the next monograde tester? Anyone? Buehler?
Good summary. Dang, I'll just delegate to you.
Wants high HTHS
Wants no VII
Want PCEO for cost
Thinks it might have more AN at lower VI
Thinks the cold crankability is actually OK
What has Cold Start High Idle/ warm Idle Oil PSI been since you made the switch? Is it a variable oil pump in our accord?
Did you see Table 2 in the SAE 922287 paper linked previously? Kind of interesting about the 3 Zones involved in cold starts and the suggested changes to J300 in Table 2 in terms of startability and pumpability max dynamic viscosity. Apparently that never happened.
I wonder were some of the normal consumer multi-viscosity oils come in for the measured MRV pumpability viscosity. That spec isn't published by companies like Valvoline, Pennzoil, Castrol, etc.
Yes, things could go much different as temperatures get lower. That's why it would be interesting to actually see the CCS and MRV dynamic viscosity of the SAE 30 and 40. That's the only real way to know how they behave without guessing/estimating. I bet HPL has ran the tests and have the numbers ... seems they would be curious themselves.
Yeah, 28F isn't too alarming. Even if it was equivalent to a 25W-40 it would theoretically be good down to -10C (14F).
What would be the coldest temperature you'd feel comfortable doing a cold start with this straight 40 grade?
Oil pressure can't always be a trusted indication that all parts requirement adequate lubrication are getting it "instantly". With cold starts and thick oil, the thing I'd be concerned about most isn't the areas of the oiling system that are force fed oil under pressure, but any parts that depend on splash lubrication, like cam-chains or piston skirts/cylinder walls (if no oil squirters) for instance.
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I've been taking notes.Good summary. Dang, I'll just delegate to you.
Wants high HTHS
Wants no VII
Want PCEO for cost
Thinks it might have more AN at lower VI
Thinks the cold crankability is actually OK
Yeah, lower VI means its viscosity vs temperature curve is steeper and viscosity change per degree is higher. But if the HTHS is still there in the high shear areas as long as the oil temperature can be kept down to a reasonable level. And the full shear viscosity will be better because there is no VII, and engines running near redline on the track could benefit from that vs say a Wx-40 or xW-50 with lots of VII. A straight 40 would still provide more MOFT protection than any xW-20 or wW-30 grade.
As far as the oil pump work and potential HP loss ... when the oil is at operating temperature any difference in that will be super insignificant because the hot viscosity will still be a 40 grade and close to each other regardless if a multi-grade or straight grade. Oil pump HP loss increases as the oil gets colder/thicker, and even then the pumping HP loss isn't that drastic, and don't know who would be running near redline with oil that's not yet at operating temp.
An in-field study like was done for J300 in the winters of 1980-1981 and 1981-1982.So who in MN or ND is signing up to be the next monograde tester? Anyone? Buehler?
K20C4 has a fixed oil pump. I have no idea what the oil pressure is because Honda only uses a switch and not a sending unit. I’m working on a way to remedy that, but I’m having to learn some arduino first. More to come on that front.
@ZeeOSix i realized I never answered your question about how cold I’m comfortable cranking. I honestly don’t know.
Frankly when we went to MN in my gx460 with the 15w-40 in, I was a bit concerned and that first crank below 20F had me nervous a bit. But it not only had instant oil pressure, the used oil analysis for the winter came back at 1ppm/1k iron. So whatever internal flow delays beyond the oil pressure light going out didn’t generate any real wear.
That built confidence and that why I was ok leaving my Accord outside down to 20f as well. Same story in the accord: instant oil pressure, very low wear on used oil analysis.
All that to say that I think my cold crank limit for this oil is a moving target. Before running the 15w, I’d have said the 15w would make me nervous around 15F.
I was searching out tech report databases and found a study of oil pressure delay as long as 40 seconds with a 15w oil. I don’t recall the test temperature, but I do recall thinking it was much warmer than such awful delay should be.
But I’m thinking now the 15w HPL is probably good to 5F or near zero. The monograde bogey just moves lower with each confidence-building start. I think right now I’m at 20f threshold of comfort with the monograde, but perhaps lower as experience justifies.
Frankly when we went to MN in my gx460 with the 15w-40 in, I was a bit concerned and that first crank below 20F had me nervous a bit. But it not only had instant oil pressure, the used oil analysis for the winter came back at 1ppm/1k iron. So whatever internal flow delays beyond the oil pressure light going out didn’t generate any real wear.
That built confidence and that why I was ok leaving my Accord outside down to 20f as well. Same story in the accord: instant oil pressure, very low wear on used oil analysis.
All that to say that I think my cold crank limit for this oil is a moving target. Before running the 15w, I’d have said the 15w would make me nervous around 15F.
I was searching out tech report databases and found a study of oil pressure delay as long as 40 seconds with a 15w oil. I don’t recall the test temperature, but I do recall thinking it was much warmer than such awful delay should be.
But I’m thinking now the 15w HPL is probably good to 5F or near zero. The monograde bogey just moves lower with each confidence-building start. I think right now I’m at 20f threshold of comfort with the monograde, but perhaps lower as experience justifies.
I think the detriment of higher viscosity is higher on the torque than is on the HP or at least is felt more easily, especially on cars with manual, and especially in the city. From my experience.
When I said qualifying I meant lap times.
You really think that you can detect a somewhat higher viscosity oil at operating temperature?
I found the graph I was looking for. I found in our archives a technical report documenting the oil pressure delay of the 5.9L and 6.7L engines at -14F with regular 15w-40 Premium Blue. It also compared it to testing at -26F with 5w-40 synthetic.
The oil pressure delay was no less than 40 seconds! Now, this was circa 2008 (right after 6.7L introduction) and both the 5.9 and 6.7L had similar oil pressure delay results.
Interestingly, the delay at -10F with conventional Premium Blue in 15w-40 was nearly identical to the delay at -26F with 5w-40 synthetic (presumably Premium Blue Extreme in CI-4+ formula).
This test data aligns pretty well with the "W" ratings since 15w is tested at -25C MRV (our -10F data is -23.3C). And the -26F data is -32.2C.
So the 5w-40 and 15w-40 had nearly identical (and long) oil pressure delays when tested at their "w" rating MRV temps.
Also, keep in mind that these test points would be approximately 10C warmer than the pour points for the respective formulations.
The oil pressure delay was no less than 40 seconds! Now, this was circa 2008 (right after 6.7L introduction) and both the 5.9 and 6.7L had similar oil pressure delay results.
Interestingly, the delay at -10F with conventional Premium Blue in 15w-40 was nearly identical to the delay at -26F with 5w-40 synthetic (presumably Premium Blue Extreme in CI-4+ formula).
This test data aligns pretty well with the "W" ratings since 15w is tested at -25C MRV (our -10F data is -23.3C). And the -26F data is -32.2C.
So the 5w-40 and 15w-40 had nearly identical (and long) oil pressure delays when tested at their "w" rating MRV temps.
Also, keep in mind that these test points would be approximately 10C warmer than the pour points for the respective formulations.
