You would be better off making an attempt to understand the technical discussion here rather than continuing to make posts that illustrate you don’t comprehend the topic.
You’re not related to engineer20 are you?
Why wouldn't a 5w50 be better than a 5w40?
- Thread starter BPU699
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You’re not related to engineer20 are you?
Here to say I love your green hatch in your avatar. Is that the Fiesta? Factory color?
Dead horse...Plenty of examples on the board.
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"If you knew the typically shape of an oil's viscosity vs temperature curve"
Id say I do know, and these curves displayed by a reputable oil supplier are typical of everything else out there:
https://penriteoil.com.au/knowledge-centre/Viscosity/237/understanding-viscosities/181.
You are welcome to provide any graphs from any manufacturer that show the contrary.
Im sure all of those oils presented there probably vary by 0.1 centistokes as well at 100 C (its not visible on that scale), but no ridiculous claims made that it represents a "thicker oil" if it does.
To move on(so you we drop the unnecessary antoganism from your yourself)
I will revise my statement, a 5W20 oil will be a thicker oil than a 0W20 oil from its cold start rating right up to near 100 C where the lower W oil will equal or could even be of marginally be of higher viscosity.
Id say I do know, and these curves displayed by a reputable oil supplier are typical of everything else out there:
https://penriteoil.com.au/knowledge-centre/Viscosity/237/understanding-viscosities/181.
You are welcome to provide any graphs from any manufacturer that show the contrary.
Im sure all of those oils presented there probably vary by 0.1 centistokes as well at 100 C (its not visible on that scale), but no ridiculous claims made that it represents a "thicker oil" if it does.
To move on(so you we drop the unnecessary antoganism from your yourself)
I will revise my statement, a 5W20 oil will be a thicker oil than a 0W20 oil from its cold start rating right up to near 100 C where the lower W oil will equal or could even be of marginally be of higher viscosity.
@mechengineer60 your inability to use the quote and reply function properly isn't doing your arguments any favors...
That's so general, not specific like the oils in post 85. Not all oils will behave like you think they will ... that's what go you going down this false claim rabbit hole. Seems you want to ignore the specs on those two oils because it proves your claim that a 5W is always going to be more viscous than a 0W all the way up to 100C. It's already been proven that is not always true like you claim it is.
Go here and put in the KV40 and KV100 of the two oils I linked in post 85, then look at the viscosity numbers. They are the same viscosity at 40C, but the 0W is more viscous from 40C to 100C, while the 5W is more viscous from 40 C to 0C. The curves cross at 40C, but opposite from your false claim.
https://www.widman.biz/English/Calculators/Graph.html
That change in your claim still is not true about the two oils in post 85. The 0W starts becoming more viscous not much warmer than at 40C, and keeps getting more viscous than the 5W as it heads for 100C. The viscosity vs temp curves are a smooth predictable curve, they don't all of a sudden jump all over the place like it would for the 0W to be suddenly thicker right before 100C. If the viscosity is going to cross over, it's going to be way before 100C.
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True this.
Ugh, smh. The small end is constantly reversing. The big end is constantly accelerating.
It’s really as simple as a higher viscosity index will allow an oil to be both thinner cold and thicker hot.
When comparing oils of disparate viscosity indices, there is almost always a temperature at which the curve cross. A high VI oil like 0w-40 ESPx4 is thicker at most temperatures than any 5w-20 or 5w-30, it’s only at extremely cold temperature that the 0w allows it to be thinner.
The monograde SAE 40 I’m using has a VI of only 117. If you get it hot enough, it will be thinner than Mobil 1 ESP 0w30.
Comparing the kv40 and kv100 shows how. The 40 grade has 123 and 14.4 values for kv40 and kv100, respectively.
Mobil 1 ESP 0w30 has 67.8 kv40 and 12.2 kv100., it will a be thicker than my HPL at a crossover temperature of about 125C.
Sure, when comparing vastly different formulated oils (including that no-VII SAE 40), all kinds of things can happen depending on the exact formulation (base oil and additives) - most people who hang out here a lot probably know that. The VI is reflective of an oil's KV40 and KV100, so just looking at those two data points tells a lot without even knowing the VI. But the false claim was a 5W-20 will always be thicker than a 0W-20 from super cold all the way up to 100C. Obviously that's not always a true statement by the examples I linked to. Some people latch on to misconceptions and never learn why they are wrong and then let it go ... it's been seen many times on this board.
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Thank you! Yes, 2023 Fiesta ST.
Original colour (Mean Green).
One of the final shipments ever to Australia from Cologne, Germany. Epic car.
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