0W20 for good protection?

[SubieRubyRoo]

Silly? You must not be familiar with the engine oiling changes that have occurred in the last 8 years with the GM LS engines. Oiling passages cast in the block for oiling on the SUCTION side of the oiling system. To be clear, my statement is relevant to GM. Don’t know or care about any other manufacturers nor do I care what oil YOU use. I use what I want and typically reflects the manufacturer’s design and recommendations. After 30 years in First Responder vehicle fleet management if nothing else you learn to use what the manufacturer recommended. Especially critical when/if filing a warranty claim. Losing funds because of denied warranty claims will ensure a Fleet Manager has a quick exit…. EDIT: Manufacturers’ Fleet Representatives called on our shop and and were the lifeline for warranty claim settlement. When they saw the adherence to their recommendations every claim was settled and they more times than not extended manufacturer’s courtesy towards out of warranty repair costs in that same vein….

There is no “suction side” of the oiling system inside an LS block; the oil pickup tube is mounted directly to the crank-driven oil pump, after which it is pressure side before it ever lubricates anything inside the engine, and has always been this way during the 25+ years since the LS’s debut.

 

[demarpaint]

The choice of word might be a legal matter.

It could very well be. All I know is when I hear the word adequate, that means there's always something better.

 

[PontiacHO]

There is no “suction side” of the oiling system inside an LS block; the oil pickup tube is mounted directly to the crank-driven oil pump, after which it is pressure side before it ever lubricates anything inside the engine, and has always been this way during the 25+ years since the LS’s debut.

Yep. My description is incorrect however these now are two stage vane pumps.

 

[Blinker]

And the reason for that is because you do not understand the topic.

Why are you on this forum exactly? You’re accusing me of not understanding because I strictly follow the owners manual?

 

[SubieRubyRoo]

Why are you on this forum exactly? You’re accusing me of not understanding because I strictly follow the owners manual?

0w30 and 10w30 are the same viscosity at operating temps. That’s why.

 

[OVERKILL]

The Skyactiv controls the oil pressure and it is controlled by a lot of inputs. One is water temperature.
https://www.hexorcism.com/16ND/sh13083/

So… you can decrease oil viscosity required if oil pressure is regulated to match the need.

Conventional oil pumps "control" (maximum) pressure too, with a pressure relief valve. There are two different mechanisms in play on the more common variable displacement pumps, depending on the OEM and the design, one changes the relief pressure to bypass more oil (reduce load on the pump) when under low load conditions, the other effectively manipulates the size of the pump itself, changing its displacement.

I do believe we discussed the Mazda one in another thread?

 

[Bill_W]

Conventional oil pumps "control" (maximum) pressure too, with a pressure relief valve. There are two different mechanisms in play on the more common variable displacement pumps, depending on the OEM and the design, one changes the relief pressure to bypass more oil (reduce load on the pump) when under low load conditions, the other effectively manipulates the size of the pump itself, changing its displacement.

I do believe we discussed the Mazda one in another thread?

So you spend your time picking the obvious that all oil pumps have a high RPM pressure relief. The point in bringing this in the conversation is the water temperature, one of the inputs. That relates to oil temperature/viscosity. Notice (if you read) the pulsing from high to normal pressure to remove the air from the oil galleries in starting. The 2 step oil pump pressure is different. Conventional oil pumps are RPM dependent. I respect your posts here but in a conversation old discussions will be used if it applies.

 

[Blinker]

• Yesterday at 11:46 PM
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• #109

I only use the oil viscosity that’s stamped on the engine oil cap. The only times I’ve used something different is when the owners manual lists alternative viscosities. I.E General Motors allowing 0W-30 in cold climates, General Motors allowing 10W-30 in the LS1 V8, and Hyundai allowing a plethora of viscosities.

0w30 and 10w30 are the same viscosity at operating temps. That’s why.

It’s evident that you’re not comprehending what I said. I said I only use what’s stamped on the engine oil cap but occasionally use a different viscosity listed in the owners manual.

0W-30 and 10W-30 can be the same thickness at operating temp but are still considered different viscosity grades. What are you not understanding?

 

[Bill7]

It's all about HTHS. Certain parts of the engine get much hotter than other parts. During high RPM's on the extremely hot parts of the engine, 20 weight oil will sheer to a very thin viscosity and you may get metal on metal contact. Since 20 weight oils start out with the HTHS of 2.6, and will typically sheer down to HTHS 2.3/2.4 during the life of the oil change cycle. Engine wear increases exponentially once HTHS is < 2.6.
I don't want a 20 weight oil in any car I own regardless of what the Manufacturer puts in their owner's manual.
The writers of the owners manual are motivated by avoiding CAFE fines, and are putting 20 weight or even 16 weight oil for all temperature ranges.
All other countries outside the US have owners manuals for the same engine(s) speced for 5W-30 or thicker.

I only use a thick 5W-30 synthetic high mileage oil (which also treats the engine seals) with at least a 11.4 or higher Viscosity at 100C
regardless of what the owner's manual's say. There is no way I will ever use a 20 weight or 16 weight or 8 weight oil in any of the cars I own.

I honestly believe following your owner's manual recommendation for viscosity is the best way to shorten the life span of your engine.
Manufacturers only care about the car getting to the 60,000 end of warranty mileage for new cars, and they care about avoiding CAFE fines.
They don't care about the car once it's out of warranty, as profit for them is paramount.

 

[OVERKILL]

So you spend your time picking the obvious that all oil pumps have a high RPM pressure relief.

Why do you think it's high RPM? The pressure relief on the pump does not only actuate when the engine is at high RPM, it does so when system pressure reaches a certain (fixed) threshold. This can be the result of temperature (viscosity), not just engine speed. Conversely, with the oil fully up to temperature, the relief may never engage, regardless of engine RPM.

The point in bringing this in the conversation is the water temperature, one of the inputs. That relates to oil temperature/viscosity.

Yes, and thick (heavier) oil increases pumping losses. So being able to modulate the bypass pressure (see point 1) during periods of low load reduces pumping losses.

Notice (if you read) the pulsing from high to normal pressure to remove the air from the oil galleries in starting.

That's a pretty minor function and seems more like a requirement due to the complex plumbing implemented for the solenoid circuit. Toyota's pump, that performs the same function, is much simpler.

The 2 step oil pump pressure is different. Conventional oil pumps are RPM dependent. I respect your posts here but in a conversation old discussions will be used if it applies.

This is still a conventional oil pump Bill, should I reply in kind ("if you read") to your assertions here?

This is the diagram of the 2-step operation of the pump. It states:

• The engine hydraulic pressure switches in two steps. When hydraulic pressure is not needed, the oil pump discharge amount is reduced by the operation of the engine oil solenoid valve.

Which falls into the first category I described in my reply that you've quoted.

The conditions for its actuation are also listed:

The diagram that shows the plumbing for this variable relief circuit still shows a traditional pump:

Which, if we go to a diagram for: https://www.mcx5.org/oil_pump_skyactiv_g_2_0_-1031.html

Indeed shows a traditional crank (chain) driven positive displacement oil pump:

 

[Shel_B]

The same people who say, when it comes to oil weight/grade always follow your owner's manual recommendations.
Will also say, when it comes to oil change intervals, disregard your owner's manual recommendations.

And when it comes to transmission fluid, use Maxlife.

 

[kschachn]

And when it comes to transmission fluid, use Maxlife.

I really like Maxlife.

 

[SubieRubyRoo]

• Yesterday at 11:46 PM
• Add bookmark
• #109

It’s evident that you’re not comprehending what I said. I said I only use what’s stamped on the engine oil cap but occasionally use a different viscosity listed in the owners manual.

0W-30 and 10W-30 can be the same thickness at operating temp but are still considered different viscosity grades. What are you not understanding?

It’s funny that you think two 30-wt oils are different viscosity grades. That’s like saying having four of one thing and two pair of another, identical thing is a different quantity.

 

[Slow Car Sport Mode]

0w30 and 10w30 oil are the same viscosity at operating temperature

And the reason for that is because you do not understand the topic.

I’m not going to argue with you, it’s not worth my time.

A little bit out of order here, but, this, to me, is approaching "Peak BITOG."

User @SubieRubyRoo made a correct statement that MANY (including a LOT of YouTubers) don't understand.. The W means "Winter" and the second half of the number is an SAE grade. Why on earth that would get an "I'm not going to argue with you" reply is beyond me, but, I know one thing, user @kschachn is great at winning the arguments, perhaps "always right" but this is approaching some of the basics of motor oil law here. The W number is separate from the second number.

Anything beyond that, we get into discussions of base oils and how 0W is achieved with higher SAE grades etc (0W-50 exists, ok) but what I saw there is just seemingly unnecessary.

Then with the 0W-20 vs 5W-30.. that's a whole another section of conversation as well, .

 

[Blinker]

It’s funny that you think two 30-wt oils are different viscosity grades. That’s like saying having four of one thing and two pair of another, identical thing is a different quantity.

0W-30 and 10W-30 are different multi viscosity grades. I still don’t know how you don’t understand that. With that being said, I only use what’s on the engine oil cap or another viscosity stated in the OM.

 

[kschachn]

0W-30 and 10W-30 are different multi viscosity grades. I still don’t know how you don’t understand that. With that being said, I only use what’s on the engine oil cap or another viscosity stated in the OM.

Just like how we don’t know how you don’t understand grade.

 

[Slow Car Sport Mode]

Just like how we don’t know how you don’t understand grade.

Willful ignorance.

 

[ZeeOSix]

You must not be familiar with the engine oiling changes that have occurred in the last 8 years with the GM LS engines. Oiling passages cast in the block for oiling on the SUCTION side of the oiling system. To be clear, my statement is relevant to GM.

How would that dictate what oil viscosity to use? Need more info. If the oil passages on the suction side of the system caused oiling system pumpability problems, it would be occurring at cold start-up when the oil is cold and thick, so that could happen regardless of what the KV100 viscosity of the oil is.

 

[ZeeOSix]

0W-30 and 10W-30 can be the same thickness at operating temp but are still considered different viscosity grades. What are you not understanding?

The are both considered 30 grade oils for the KV100 spec. The W rating is different, but the W rating has absolutely nothing to do with the hot KV100 grade/rating. That was covered a long time ago.

 

[Jimmy_Russells]

You seem to be intentionally torpedoing the nuance here.

Per your assertion: "Every expensive sports car would be travelling with the thickest oil. They don't, not even in racing,"

Well, for the longest time BMW's M-cars called for 10W-60. Ford's GT and all of their performance engines call for 5W-50. GM called for 15W-50 in the Corvette and Camaro if you were racing them. The SRT HEMI's all call for 0W-40 (as does the current Corvette) while their more pedestrian siblings call for 0W-20. Many of the Euro marques like Porsche were already using 0W-40. Have you checked the oil requirements for a Ferrari?

So yes, a lot of expensive sports cars do in fact call for heavier oils.

On the "cold start" you stated: "Where does the biggest wear occur again? Right at the cold start"

Do you know why exception was taken to that statement? It's because it again doesn't adequately address the nuance of what transpires, which should really be called "warm-up wear", which may give you a hint as to there being additional mechanisms in play that result in increased wear while the engine and oil are not up to temperature.

I'm not sure that is a good example to be using. Literally an example where using too thick of an oil caused/causes engine damage.