5W20 vs 5W30 in the Midwest for a car that frequently takes long trips

[GT Pony]

Understanding Viscosities

The number in front of the “W” signifies the viscosity of the oil at cold/start up temperature (tested at -10 to -35°C depending on the grade. Please refer to the SAE J300 - Engine Oils Chart opposite). The lower the first number, the faster the oil flows (pumpability) when the engine is cold.

The second number represents the oil’s thickness at operating temperature (100°C). All oils thin out as they get hotter.
So, the higher the second number, the less the oil will thin out as it heats up, compared to an oil with a lower second number.
Normally, multigrade viscosities are measured on a curve.

Wherever you snatched that from isn't quite there technically.

The number in front of the "W" does NOT signify the actual viscosity as they mention. It only signifies a "W" Grade rating. The W grade specifications shown in the SAE J300 table is based only on a max viscosity limit for each defined W grade at a certain test temperature, and the oil's actual viscosity is determined by a special CCS and MRV dynamic test machine. It is not based on how the oil flows under gravity.

What determines how much the oil will thin out as it heats up is the viscosity index, which is based on the how much and what type of VIIs were used to make it a multi-viscosity oil.

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[K4fxd]

https://penriteoil.com.au/knowledge-centre/Viscosity/237/what-is-an-sae-viscosity/180

Brian from BND says the same thing. We had a long discussion on oils for a non forced air cooled race car. Oil temps get into the 400's

I may not be an oil expert but I do understand it.

 

[luc]

Wherever you snatched that from isn't quite there technically.

The number in front of the "W" does NOT signify the actual viscosity as they mention. It only signifies a "W" Grade rating. The W grade specifications shown in the SAE J300 table is based only on a max viscosity limit for each defined W grade at a certain test temperature, and the oil's actual viscosity is determined by a special CCS and MRV dynamic test machine. It is not based on how the oil flows under gravity.

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"So, the higher the second number, the less the oil will thin out as it heats up, compared to an oil with a lower second number."

^^^ Is that your claim? If so, it's wrong because the second number (like 30 in 5W-30) only signifies the hot KV100 viscosity grade, as defined in SAE J300, regardless of that the W grade of it is.

What determines how much the oil will thin out as it heats up is the viscosity index, which is based on the how much and what type of VIIs were used to make it a multi-viscosity oil.

Seriously!!!! Can you just drop it????
First number is an indication of flow at low temp, a 0 will flow faster than a 20
The second number is an indication of the oil “thinning “ at high temperatures
A 20 will be thinner than a 50
Can you please now stop it ????

 

[GT Pony]

There's a lot of misinformation even like this on the 'net. Words and terms matter when talking about technical subject matter. There is not an actual viscosity number except for just the max dynamic (cP units) viscosity limit associated with the W grade side of a multi-viscosity oil.

Look at the SAE J300 table ... it's right there in the Cold Cranking and Pumpability (Max Viscosity) columns defining the W grades. If an oil tested at -30C for CCS and -35C for MRV has a dynamic viscosity (as measured in the special CCS and MRV machines) of 6600 cP or less for CCS and also 60,000 cP or less for MRV, then it's a 5W grade oil. No "cold flow" testing involved, only dynamic shearing done in special test machines determine how it behaves in an engine at very cold temperatures.

 

[GT Pony]

Seriously!!!! Can you just drop it????
First number is an indication of flow at low temp, a 0 will flow faster than a 20
The second number is an indication of the oil “thinning “ at high temperatures
A 20 will be thinner than a 50
Can you please now stop it ????

Better re-read what I said. You might be misundertanding who's saying what. What part of what I said do you think I'm wrong about? ... be specific. Read carefully.

Again, the W rating is NOT determined by how it "flows" at cold temperature . Read the post right about this one. The W rating is determined by dynamically shearing the oil when cold in very special test machines. Do some research if you don't believe it.

 

[furdfan2018]

Great thread






Not

 

[MAGS1]

 

[WildHorse]

So, the higher the second number, the less the oil will thin out as it heats up, compared to an oil with a lower second number

Already explained how that process works .

 

[PoCoBob]

This thread should go into the most useless thread hall of fame.

 

[luc]

Better re-read what I said. You might be misundertanding who's saying what. What part of what I said do you think I'm wrong about? ... be specific. Read carefully.

Again, the W rating is NOT determined by how it "flows" at cold temperature . Read the post right about this one. The W rating is determined by dynamically shearing the oil when cold in very special test machines. Do some research if you don't believe it.

What are you trying to prove?
That you know more than anyone else?
You are becoming very boring and pedantic
My last post on this subject… don’t want to be encouraging mental masturbation

 

[Nitrousfedlx]

@Nickyweg trying to unfuck ur thread. 2 biggest pro's for 5w20 and 5w30 from researching is this. 5w20 will get through the motor a tad faster thus lubricating the internals faster. 5w30 on the other hand provides a tad bit better protection at higher temps. My 2 cents is, if ur changing oil like u should be, (no more than 5k mile intervals with a good brand full synthetic) u can't go wrong with either weight in a N/A car.

 

[GT Pony]

What are you trying to prove?
That you know more than anyone else?
You are becoming very boring and pedantic
My last post on this subject… don’t want to be encouraging mental masturbation

Just clarifying technical information ... too much misconception about multi-viscosity oil (no surprise really). Sorry you can't keep up in the discussion or don't want to expand your oil knowledge, and instead jump in the middle trying to say something is wrong when it isn't, lol

 

[GT Pony]

2 biggest pro's for 5w20 and 5w30 from researching is this. 5w20 will get through the motor a tad faster thus lubricating the internals faster.

No worries moving hot oil with a positive displacement oil pump that forces the same volume through the oiling system. It's more important to have that added viscosity the xW-30 gives as you mentioned.

 

[WildHorse]

 

[JetGray_Mach1]

You guys and your damn oil threads.

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