yeah right LOL
HTHS
- Thread starter MolaKule
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Thought I would bump this back to the top as it is a good read.
Very good read, thank you
Wow. I'm speachless. Mostly because I can't spell most of the big words in this thread, even after I read them!
Back to the HTHS discussion...it appears that 2.6 is the minimum allowed under API SM...is this correct (for 5W-20)? I share the wishful thinking of one of the earlier posters in this thread, that it'd be nice if engine manufacturers published the minimum HTHS requirements with their engines. But if they certify their engines to use API SM oil, I guess they're indirectly saying that you need at least a 2.6, yes?
My question is relative to older engines, designed to use SL oil (my Corolla, for example), and I believe SJ (my Dakota). Does the SM oils meet the earlier API requirements for HTHS, if those earlier API specs even INCLUDED HTHS?
Bottom line: my Corolla wants a 5W-30 SL, according to the oil fill cap. Toyota now recommends a 5W-20 SM. HTHS is non-trivially lower in 5W-20 vs. 5W-30. I guess I shouldn't worry about it, since 5W-20 is now Toyota's official recommendation, huh?
Back to the HTHS discussion...it appears that 2.6 is the minimum allowed under API SM...is this correct (for 5W-20)? I share the wishful thinking of one of the earlier posters in this thread, that it'd be nice if engine manufacturers published the minimum HTHS requirements with their engines. But if they certify their engines to use API SM oil, I guess they're indirectly saying that you need at least a 2.6, yes?
My question is relative to older engines, designed to use SL oil (my Corolla, for example), and I believe SJ (my Dakota). Does the SM oils meet the earlier API requirements for HTHS, if those earlier API specs even INCLUDED HTHS?
Bottom line: my Corolla wants a 5W-30 SL, according to the oil fill cap. Toyota now recommends a 5W-20 SM. HTHS is non-trivially lower in 5W-20 vs. 5W-30. I guess I shouldn't worry about it, since 5W-20 is now Toyota's official recommendation, huh?
API SM oils will work well in all of the vehicles you have listed. If Toyota has a TSB out about using 5W-20 for your Corolla I would go ahead and use it. If the oil cap on your 07 Corolla says to use API SL rated oil, then I would think they are just using up the overstocked inventory of oil filler caps they have.
Thanks Johnny. I plan to continue to use Rotella 10W-30 in my Dakota, with a bottle of STP added. It seems to keep the rear main seal from leaking. And it's a good stout oil for the ol' 318 V-8 with almost 175,000 miles on it.
Currently have PP 5W-20 in the Corolla, but am changing oil this weekend. Will use YB, but haven't quite decided on 5W-20 vs. 5W-30. According to most things I've read here, there's no real fuel economy benefit in the 5W-20, and the better HTHS of the 5W-30 might be beneficial over the long run.
Currently have PP 5W-20 in the Corolla, but am changing oil this weekend. Will use YB, but haven't quite decided on 5W-20 vs. 5W-30. According to most things I've read here, there's no real fuel economy benefit in the 5W-20, and the better HTHS of the 5W-30 might be beneficial over the long run.
Quote:
I plan to continue to use Rotella 10W-30 in my Dakota, with a bottle of STP added.
Why not just use a 40 or 50 grade?
I plan to continue to use Rotella 10W-30 in my Dakota, with a bottle of STP added.
Why not just use a 40 or 50 grade?
Im thinking that would be close to the same as just using the 15w40 Rotella....
What do I gain with the 15W-40 vs. the 10W-30? You mean use the thicker weight instead of using the seal conditioner? Although I live in North Carolina, we still have 15-20 deg F mornings and I'm not sure 15W-40 is going to be best for my starter/battery. I know the Rotella 10W-30 is already likely "thicker" than most 10W-30 oils out there (I know it is at 100 deg C, and I'm positive it is at 40 deg C, although a spec isn't listed by Shell at that temperature).
I changed the oil in the Dakota last weekend with a concoction of stuff I had left on the shelf. Including a quart of 30W Rotella, two quarts of GC 0W-30, and two quarts of SynPower 5W-30. The rear main seal started leaking pretty much immediately...a few drips on the driveway at night. Rotella 10W-30 was in it before, and not leaking. So I figure I want to run the thinnest oil I can without the rear main leaks. I actually changed the oil last night, dumped a gallon of Rotella 10W-30 in it with some Stabil seal conditioner. That should do the trick for now.
I change oil in this truck every 2,000 miles. Just because of the high miles, the infrequency of driving, and the short trips it often makes. If I'd really be better served by the 15W-40, I'm all ears.
Thanks.
I changed the oil in the Dakota last weekend with a concoction of stuff I had left on the shelf. Including a quart of 30W Rotella, two quarts of GC 0W-30, and two quarts of SynPower 5W-30. The rear main seal started leaking pretty much immediately...a few drips on the driveway at night. Rotella 10W-30 was in it before, and not leaking. So I figure I want to run the thinnest oil I can without the rear main leaks. I actually changed the oil last night, dumped a gallon of Rotella 10W-30 in it with some Stabil seal conditioner. That should do the trick for now.
I change oil in this truck every 2,000 miles. Just because of the high miles, the infrequency of driving, and the short trips it often makes. If I'd really be better served by the 15W-40, I'm all ears.
Thanks.
bump 
Originally Posted By: arihel
Molakule: Do you have the reference for the mass loss values given in your earlier post? I would like to see the full article.
Thanks in advance.
^^^^^^ ???????
And FWIW, the wear results must be in micrograms. There's no way a connecting rod bearing lost over 1/3 of a pound (190 grams). I doubt they even weigh over 40 grams...
So, assuming 40 grams for a connecting rod bearing and micrograms for the wear results, the wear is 0.475% vs 0.07%. Greater wear rate? Indeed. Is it really significant at those levels?
Also, those results weren't run on an engine designed to run on 0W20 oil nor were they done on an engine running oil with a SAE minimum HTHS of 2.6.
I'm pretty sure the same wear test results when run on an engine designed to run on 0W20 oil would be insignificant when comparing oil of 2.6 HTHS to an oil of 3.2 (or even higher) HTHS...
Bottom line: IMHO, under normal use no one should be the least bit concerned about running 0W20 oil in engines designed to run on said oil.
Molakule: Do you have the reference for the mass loss values given in your earlier post? I would like to see the full article.
Thanks in advance.
^^^^^^ ???????
And FWIW, the wear results must be in micrograms. There's no way a connecting rod bearing lost over 1/3 of a pound (190 grams). I doubt they even weigh over 40 grams...
So, assuming 40 grams for a connecting rod bearing and micrograms for the wear results, the wear is 0.475% vs 0.07%. Greater wear rate? Indeed. Is it really significant at those levels?
Also, those results weren't run on an engine designed to run on 0W20 oil nor were they done on an engine running oil with a SAE minimum HTHS of 2.6.
I'm pretty sure the same wear test results when run on an engine designed to run on 0W20 oil would be insignificant when comparing oil of 2.6 HTHS to an oil of 3.2 (or even higher) HTHS...
Bottom line: IMHO, under normal use no one should be the least bit concerned about running 0W20 oil in engines designed to run on said oil.
Is it available to have SAE 0W-20 and ACEA A3 (HTHS>=3.5) the same time?
For example:
http://www.eurol.com/en/37-products/659-eurol-super-lite-5w-20.html
http://www.eurol.com/en/productfiles/pi/659-eurol-super-lite-5w-20.pdf
For example:
http://www.eurol.com/en/37-products/659-eurol-super-lite-5w-20.html
http://www.eurol.com/en/productfiles/pi/659-eurol-super-lite-5w-20.pdf
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Originally Posted By: moribundman
3. Why was this spec introduced?
Sufficiently high enough HTHS viscosity ensures that lubrication in bearings does not suffer under high pressure and high temperatures.
The HTHS viscosity relates quite well with MEASURED (not calculated) oil film thickness ,KV does not always relate very well and is sometimes totally incorrect.
3. Why was this spec introduced?
Sufficiently high enough HTHS viscosity ensures that lubrication in bearings does not suffer under high pressure and high temperatures.
The HTHS viscosity relates quite well with MEASURED (not calculated) oil film thickness ,KV does not always relate very well and is sometimes totally incorrect.
Izb said:
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