The MaxLife 10w-40 in my '98 resembles this remark...
What is considered a respectable HTHS?
- Thread starter Carlostrece
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The MaxLife 10w-40 in my '98 resembles this remark...
Ok thanks. I swore I read that HTHS had a cap for API rated oils because it impacted fuel economy too much.
Carlostrece
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That's useful info!
I don’t believe the API does anything like that but I could be wrong. SAE and manufacturer approvals, yes.
I think I'm wrong about this. However, you won't see API SP 5W-30 oils with an HTHS >3.5 because SP prioritizes fuel economy. I'm not aware of any.
Carlostrece
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I don't want a 5w40, but you got me thinking. I just compared the KV100 cSt of Quaker State UPFS 5w-30 to QS Euro L 5w-30.
QSUPFS 11.7 cST
QSEL 13 cSt
Most other 5w-30 USA syn oils are from 10 to 10.5 cSt.
Wow those QS # are good/high cSt @ 100C for 5w30 synthetic oils, especially for the excellent prices they're available at Walmart.
This makes me realize a couple things. There's a definate connection between KV100 high cSt and high HTHS. It appears to me that Euro oils are (at least in part) relying on having higher cSt @ KV100 to get a higher HTHS number.
So I think I'm correct in liking 5w30 synthetic with high cSt @ KV100. In the past I liked it mainly because thicker is less likely to leak in an old car, but now I'm also seeing the HTHS lubrication benefits too.
Of course I also like it to be thin enough at KV40 too.
M1 FS and ESP in 30 grades meet the performance requirements of SP (LSPI, TGDI chain wear).
I don't think you really need to read the tea leaves like that. There are very stringent Euro approval tests that are peformed. Just pick something MB 229.5 or .51 or .52, LL-04, or VW 504.
I think there's a difference between "meets requirements" and "carries approvals."
ESP 5W-30 for sure has an API license. It is the 0W-30 that only meets the engine test requirements, not the bench portion. I believe the 0W-30 has a slightly high phosphorus level, which might be considered a feature instead of a bug.
"Meets requirements" is proper language for an API license. You can always verify against the EOLCS Directory. An API license is not an approval.
Valvoline FS High Mileage 5w30 has a HTHS of 3.2. The same oil in 10w30 has a HTHS of 3.3. Mobil 1 High Milage in 10w30 is 3.5. All these oils would work well in your application.
I would rather have the 3.5 versus the 3.2 or 3.3!
Remember I said "Meets the performance requirements". FS for example can't meet the formulation requirements (Phosphorus levels iirc), but that doesn't mean it can't pass the relevant tests under SP. API isn't a high bar and just required a formulation change which includes replacing some amount of Ca with Mg. API SN oils were predominantly Ca only.
Good point. I missed that subtle wording difference. Thanks.
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What is your car? My cool as cucumber Sienna does great with 2.3
Respect is earned, not given. That means no 20 grade for me!
You may have to go slowly uphill in a loaded car during summer time in the 2nd gear (i.e. high RPM) with not much airflow ... or have to give someone a ride via Death Valley.
That means Euro baby!
You may have to go slowly uphill in a loaded car during summer time in the 2nd gear (i.e. high RPM) with not much airflow ... or have to give someone a ride via Death Valley.
That means Euro baby!
Have to be careful with context when talking about the correlation between HTHS viscosity and engine wear. It has to be looked at under the same conditions, like for instance the oil being the same temperature and under the same shear rate in a bearing or between two moving parts. An oil with less HTHS viscosity under those same operating conditions will result in a smaller film thickness between the moving parts, and therefore have the possibility of more wear. Wear control is all about separating moving parts with an adequate film thickness between parts to minimize rubbing and wear, and also the film strength of the oil which is what mitigates wear when two moving surfaces start rubbing on each other when the film thickness goes to zero.
Of course if you have some 0W-8 and run it though an effective oil cooler to keep the oil temperature down, then it's gong to result in more viscosity and therefore more film thickness between parts. That's just making the operating hot viscosity higher by keeping the oil cooler. But if you ran that 0W-8 at 250F operating temperature it's not going to provide the same film thickness between moving parts as say a 0W-40 or any other thicker oil would at that same 250F operating temperature. That's the context that needs to be used when comparing engine protection vs the HTHS viscosity factor.
Studies do show that more wear can result in most engine components as the HTHS viscosity gets lower ... typically when it starts getting around 2.4 cP and below. This is why engines that specify 0W-16 and lower oil grades use some special engine design features to help decrease wear when the film thickness becomes lower as the viscosity becomes lower.
I got this.....
It is of course the plan that an oil pump makes, during operations, to .......well, pump oil and stuff. It has limited options though.
And to add, not by much at all. The hydraulic pumping HP difference is hair splitting at best ... running the numbers shows this. Also, variable displacement oil pumps try to minimize oil flow to low as possible. I'd rather have an old fashioned oil pump that pumps way more oil flow than the minimum and I'll take the 0.05 MPG drop in fuel economy.
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