One Dodge running 5W20 rewrites all the engineering texts in history ?

[OVERKILL]

Originally Posted by StevieC
GM has had a long history of screw-ups and making their customers foot the bill.


They've had several, yes. And this is stuff there should have been recalls for as it soured a lot of people on the brand. The intake gasket fiasco is probably the biggest one I can think of.

GM has a more sordid track record than Toyota, I'm not stating otherwise, but they have had some really good products too. We can malign them for their follies, certainly, but I give them credit for their efforts with the Corvette and Camaro, despite me finding the latter utterly repulsive. It's performance and handling are excellent. GM CAN build world class, it's the inconsistency in the execution and "what ifs" on the after support that's scary.

 

[oldhp]

Interesting reading from all the "oil aficionado's". I have the most definite proof that 5W30 is better than 5W20.
When I pull up at Dairy Queen, both my 3.6 engines are quieter. Therefore 5W30 is better than 5W20.☺

 

[StevieC]

Originally Posted by OVERKILL
Originally Posted by StevieC
GM has had a long history of screw-ups and making their customers foot the bill.


They've had several, yes. And this is stuff there should have been recalls for as it soured a lot of people on the brand. The intake gasket fiasco is probably the biggest one I can think of.

GM has a more sordid track record than Toyota, I'm not stating otherwise, but they have had some really good products too. We can malign them for their follies, certainly, but I give them credit for their efforts with the Corvette and Camaro, despite me finding the latter utterly repulsive. It's performance and handling are excellent. GM CAN build world class, it's the inconsistency in the execution and "what ifs" on the after support that's scary.



The 454, 4.3's, 3800 series, 3100 series (after the gasket issue) to name a few were all great engines and yes they have and had some really great models. But I'm talking more about how their track record overall. Yes I agree the inconsistencies as well.

 

[ZeeOSix]

Originally Posted by JAG
I think there is a disconnect between the scientific types and the non-scientific types. I think we need more tribology understanding.

Question for anyone: Reducing viscosity by 10%, affects the minimum oil film thickness in a journal bearing by approximately how much?


This table gives you an idea of how much MOFT reduction you get as you go down in viscosity.

 

[nap]

Yep it was trick question.... depends on rpm.... at 0 rpm thin oil would be as good as any lol

 

[JAG]

nap, it's not a trick question. Assume we are comparing the two oils at the same rpm and load.

ZeeOSix, that table is great data and we need to keep sharing such things. I get the feeling that some don't understand the basics of lubrication, so asked the question to hopefully foster some learning about it. Starting with journal bearings is easiest so we start with that.

 

[ZeeOSix]

Originally Posted by nap
Yep it was trick question.... depends on rpm....


Compare at the same case conditions ... in all cases, thinner oil viscosity gives lower MOFT. It also shows that revving the [censored] out of an engine with 0W-20 helps protect the bearings ...

 

[OVERKILL]

Originally Posted by JAG
I think there is a disconnect between the scientific types and the non-scientific types. I think we need more tribology understanding.

Question for anyone: Reducing viscosity by 10%, affects the minimum oil film thickness in a journal bearing by approximately how much?


Agreed.

Regarding the bearing, we need the speed, load and specs as well as the reference viscosity.

 

[OVERKILL]

Originally Posted by ZeeOSix
Originally Posted by JAG
I think there is a disconnect between the scientific types and the non-scientific types. I think we need more tribology understanding.

Question for anyone: Reducing viscosity by 10%, affects the minimum oil film thickness in a journal bearing by approximately how much?


This table gives you an idea of how much MOFT reduction you get as you go down in viscosity.


That demonstrates the issues with lugging quite well actually

 

[Nickdfresh]

Originally Posted by ZeeOSix
Originally Posted by JAG
I think there is a disconnect between the scientific types and the non-scientific types. I think we need more tribology understanding.

Question for anyone: Reducing viscosity by 10%, affects the minimum oil film thickness in a journal bearing by approximately how much?


This table gives you an idea of how much MOFT reduction you get as you go down in viscosity.



Whose 0W-20 did they use? Because I'm pretty sure there is some data floating around here regarding "0W-20" in which the "experimenters" formulated their own "0W-20" since none actually existed when the test took place. No offense intended and I genuinely don't know if this is from that or not, but just saying....

 

[4WD]

GM

Traded 2010 5.3L that ran 5w30
Just got 2018 5.3L … now my 2nd 5.3L (have 2017) with 0w20 on the fill cap

Changes?
Oil cooler, piston oil jets, new oil pump design, up to 8 quarts from 6 quarts, spec'd 0w20 (made from better base stock)
OLM goes to 7k … good by me on DI engines … no UOA's …

 

[wemay]

Why are flow rates different if we're looking at a positive displacement oil pump? Not being cheeky, serious question.

 

[JAG]

The reference viscosity is x. The reduced viscosity is 0.9x. You don't need other viscosity specs. because those are the viscosities at the shear rate and temperature imposed by the bearings.

 

[Nickdfresh]

Originally Posted by JAG
nap, it's not a trick question. Assume we are comparing the two oils at the same rpm and load.

ZeeOSix, that table is great data and we need to keep sharing such things. I get the feeling that some don't understand the basics of lubrication, so asked the question to hopefully foster some learning about it. Starting with journal bearings is easiest so we start with that.



Sure, great data. Where is the 5W-20 and 5W-30?

 

[nap]

o
Originally Posted by JAG
nap, it's not a trick question. Assume we are comparing the two oils at the same rpm and load.

ZeeOSix, that table is great data and we need to keep sharing such things. I get the feeling that some don't understand the basics of lubrication, so asked the question to hopefully foster some learning about it. Starting with journal bearings is easiest so we start with that.


Ok I'll bite and post this link, it presents the stuff as charts so it's easier to digest:

http://www.substech.com/dokuwiki/do...ngs#effect_on_minimum_oil_film_thickness

 

[clinebarger]

Originally Posted by 4WD
GM

Traded 2010 5.3L that ran 5w30
Just got 2018 5.3L … now my 2nd 5.3L (have 2017) with 0w20 on the fill cap

Changes?
Oil cooler, piston oil jets, new oil pump design, up to 8 quarts from 6 quarts, spec'd 0w20 (made from better base stock)
OLM goes to 7k … good by me on DI engines … no UOA's …


Gen V engines in Corvette & Camaro call for 5w30.....The LT1 in the Camaro SS holds 10 quarts of oil.

 

[4WD]

I know … my boss has a C7 … but I could of also added how much more power my new 5.3L's have over the ‘10… my point is GM did not just send out an email and change to 20 grade …

 

[clinebarger]

Originally Posted by 4WD
I know … my boss has a C7 … but I could of also added how much more power my new 5.3L's have over the ‘10… my point is GM did not just send out an email and change to 20 grade …


I don't see ANY reason for the Xw20 weight recommendation for the Ecotec3 engines other than fuel economy target numbers? All internal clearances, Oil Pump, & Oil Pump "flow control" Maps are identical across the board barring the dry sump engines.

 

[SubieRubyRoo]

I still want to see a video of an engine imploding... it must have used that "black hole" oil filter from another thread LOLOL

As much as I like PUP, which I have used almost exclusively for 100k miles in 0W20 and 5W20 flavors (PP & M1 accounted for about 3 OCI total), and had pretty dang good UOAs for the mileage to show for it, I recently just before my last OCI happened to pull the oil cap and the cam had stopped with the "leading" ramp facing up towards the oil hole. I was aghast when I saw that a spot on the ramp, about 3/8" wide, was extremely shiny and significantly different looking than some of the other 2.3/2.5 engines with valve cover pics I have seen with significantly more mileage and generally reporting thicker oil usage. It is where the cam lobe goes from the base circle to the ramp... and the tip of the lobe does not look like this. I believe it's from the scuffing action as the cam slides across the follower, and while I couldn't catch a nail on the surface, it was disconcerting. I pulled up Amazon and ordered a jug of Ravenol DXG which is currently in the sump.

It may or may not be anything actually worth getting worked up about, but any time I see scuffing/polishing significantly different than the rest of the lobe it worries me. Time will tell, but physics is physics. Once the load exceeds the film strength of the lubricant, bad things begin to happen, regardless of how long it actually takes to fail. Thicker oils generally have more robust film strength.

 

[Revving2Redline]

Feeling pretty good using redline and archoil. Might go to 0w30 once I get to 400k. Almost to 200k by Xmas and to the Moon by May 238,900 mi.