Thin vs Thick Discussion Chapter 1

Messages
41
Location
Pittsburgh
Oil being "thick" at lower temperature is not a problem at all. Internal combustion motors create heat, modern turbos create a TON of heat. I want an oil to maintain viscosity at over 300f. Gokhan even has a chart showing full shear of oil to show how oil holds up inside a motor in places with tight tolerances and extreme pressure.
If start up wear was so bad then manufacturers would spec 0w16 oil.
This isn't the case, we have vehicles with turbos making well over 200hp per litre.
If you ran a 0w16 in a car designed for 5w30 it would have 10x the wear during operation vs start up.
 

AEHaas

Thread starter
Messages
1,420
Location
Sarasota, Florida
"If you ran a 0w16 in a car designed for 5w30 it would have 10x the wear during operation vs start up."

You may want to read this thread:

Dropping from a 60 Grade to a 20 Grade Oil Revisited​


 

4WD

Messages
16,806
Location
Texas
It absolutely does stand for Winter, and has forever ... go do some searching for the right answer and you'll see.
Besides … think I just ran completely out of sports I care about … so less W’s to worry about 😷
 
Messages
27,494
Location
PNW
In fact the relationship between pressure and flow is in opposition. If you change your oil to a thicker formula the pressure will go up. It goes up because the resistance to flow is greater and in fact the flow must go down in order for the pressure to go up. They are inversely related. Conversely if you choose a thinner oil then the pressure will go down. This can only occur if the flow has increased.
How can the pressure go up if the flow decreases, and how can the the pressure go down if the flow increases when a PD oil pump is moving the oil?
 
Messages
3,349
Location
BC, Canada
Most of us were past the 10 when cold and 30 when hot concept 30 years ago when 10w30 was considered a thin oil.
When I go out to start an old beater, I'll pour gasoline down the carburator. That's why I have no hair and fuel dilution issues.

Besides the recommended 15w40 in Duramax (s), I tried and UOA'd 10w40 pcmo, SAE 30 & 40.
The 10w40 sheared from 15.4 to 11.8 in 9,000 miles. The SAE 30 gained from 11.2 to 11.6.
The SAE 40 lost a little from the published spec, but showed single digit Fe after 10,000 miles.
All Petro-Canada, but I doubt if other brands would be much different.
I have an unopened pail of Duron 10w40 I'll have to try out before it's stale dated.
I would imagine it's much more shear stable than their 10w40 car oil.
 
Messages
2,870
Location
pa
a good refresher for sure, thanks to all for the info links included. will be reading 2 + 3 as well as any that follow
 
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