The importance of oil Temperature in Determining what Viscosity of oil to run.

[Rand]

I wanted a viscosity buffer for fuel dilution in my FA24DIT engine. (260hp turbo)
Note: all temps in Celsius convert if you need F
I was expecting oil temps higher than my FB25(182hp naturally aspirated) powered Subarus which ran between 105C and 115C in normal driving.
So I picked M1 0w30 ESP which is a 12.2cst oil@100c

I found out as I drove my fa24dit powered outback that the oil temps rarely reach 100c and really live between 88C-95C
Even in the summer in conditions that would push my FB25 oil temp near 115C (towing w/ac etc) I never went higher than 98C

If you look at the supplied Chart You will notice that 0w20 at 95C is nearly the same as m1 ep 5w30 at 105C.

I'll let you draw your own conclusions from this .

My conclusions were:
1. M1 EP 5w30 - 10.2cst was thick enough to provide a decent viscosity buffer against fuel dilution.. in my application due to its lower than expected oil temps.
no need for the 12.2cst M1 ESP

2. If there ever was a turbo engine that 0w20 was adequate for.. its possibly the FA24dit. (still not buying that one 100%)

 

[RooflessVW]

1. Splitting hairs

2. More thicker, more better

 

[wwillson]

The engine oil in my 3.0L Duramax runs about 250F or 121C on the interstate. The 0w-20 would have a viscosity of about 5.9 cSt at that temperature. If my use was interstate all the time I would run HPL 15w-40 CC and get a viscosity of about 9.0 cSt, which is approximately the same viscosity as a 20wt at 100C.

 

[FreedomOne]

The engine oil in my 3.0L Duramax runs about 250F or 121C on the interstate. The 0w-20 would have a viscosity of about 5.9 cSt at that temperature. If my use was interstate all the time I would run HPL 15w-40 CC and get a viscosity of about 9.0 cSt, which is approximately the same viscosity as a 20wt at 100C.

Aren't you running HPLs 5w30 Dexos now?

 

[Jetronic]

The engine oil in my 3.0L Duramax runs about 250F or 121C on the interstate. The 0w-20 would have a viscosity of about 5.9 cSt at that temperature. If my use was interstate all the time I would run HPL 15w-40 CC and get a viscosity of about 9.0 cSt, which is approximately the same viscosity as a 20wt at 100C.

GM uses dexos D 0W-20 in their 1.6 diesels aswell, didn't like the look of the bearings in the "I do cars" teardown of one. Specifically the top half of the conrod bearing that takes the combustion loads. Those engines run forever with a higher viscosity oil (and with a timing belt instead of a chain on the gearbox side). The cruze diesels had a 2.0 from a previous generation with the belt.

video starts when he gets to the bearings, this engine was from an equinox

 

[Jetronic]

View attachment 254655
I wanted a viscosity buffer for fuel dilution in my FA24DIT engine. (260hp turbo)
Note: all temps in Celsius convert if you need F
I was expecting oil temps higher than my FB25(182hp naturally aspirated) powered Subarus which ran between 105C and 115C in normal driving.
So I picked M1 0w30 ESP which is a 12.2cst oil@100c

I found out as I drove my fa24dit powered outback that the oil temps rarely reach 100c and really live between 88C-95C
Even in the summer in conditions that would push my FB25 oil temp near 115C (towing w/ac etc) I never went higher than 98C

If you look at the supplied Chart You will notice that 0w20 at 95C is nearly the same as m1 ep 5w30 at 105C.

I'll let you draw your own conclusions from this .

My conclusions were:
1. M1 EP 5w30 - 10.2cst was thick enough to provide a decent viscosity buffer against fuel dilution.. in my application due to its lower than expected oil temps.
no need for the 12.2cst M1 ESP

2. If there ever was a turbo engine that 0w20 was adequate for.. its possibly the FA24dit. (still not buying that one 100%)

Excellent oil temps, that's where I want my oil to live aswell. That's the bulk oil temp, or the coldest any of it is. Oil returning to the sump will be hotter, and will get rid of any moisture, but overall oil aging is kept to a minimum.

I'd still pick 12cst oil over 10 cst, all else being equal. and I did actually, running a 10W-30 12cst oil in my ecotec powered MG, that comes with 0W-20 from the factory. this 10W-30 oil is mainly made of 10cst PAO and has properties very close to that.

 

[JavierH19]

More thicker, more better

^this

 

[Rand]

I had a jug of API sp m1 EP 5w30 in the basement


I also have more M1 0w30 esp.
It'll probably make a return next April.
I found it interesting that in a few degrees C the difference between 0w20 and 5w30 disappears.
Even 0w20 vs 0w40.
Which if my car was a WRX (Same engine) and it saw some track time, I would definitely be using a 40wt.

 

[Jetronic]

I had a jug of API sp m1 EP 5w30 in the basement


I also have more M1 0w30 esp.
It'll probably make a return next April.
I found it interesting that in a few degrees C the difference between 0w20 and 5w30 disappears.
Even 0w20 vs 0w40.
Which if my car was a WRX (Same engine) and it saw some track time, I would definitely be using a 40wt.

yes per grade you can run about 10°C hotter and end up with the same viscosity. The difference between 0W-30ESP and 0W-40 is smaller, but they both straddle the cut-off between a 30 and 40 grade so to be expected.

 

[Snagglefoot]

Chevy specifies 0w20 motor oil for their LT engines including the 6.2 liter engine making about 420 HP. Does anyone have a cruising oil temp reading from it? That way we can armchare engineer it as well.

 

[TiGeo]

137C (280 F) is as high as I have seen on track in the Sportwagen with HPL Euro 5W40. So ~7 cSt.

 

[Snagglefoot]

GM uses dexos D 0W-20 in their 1.6 diesels aswell, didn't like the look of the bearings in the "I do cars" teardown of one. Specifically the top half of the conrod bearing that takes the combustion loads. Those engines run forever with a higher viscosity oil (and with a timing belt instead of a chain on the gearbox side). The cruze diesels had a 2.0 from a previous generation with the belt.

video starts when

What we need is some data from folks who ran higher viscosities and what mileage they achieved. “ those engines run forever” is just Internet hyperbole.

 

[Jetronic]

What we need is some data from folks who ran higher viscosities and what mileage they achieved. “ those engines run forever” is just Internet hyperbole.

https://www.spritmonitor.de/en/detail/1560000.html

and compared to other similar cars:

https://www.spritmonitor.de/en/over...2022&constyear_e=2026&power_s=114&power_e=124

You'll find I seem to have the best fuel consumption of the lot, and I'm running 10W-30 >3.5 HTHS oil

 

[kschachn]

What we need is some data from folks who ran higher viscosities and what mileage they achieved. “ those engines run forever” is just Internet hyperbole.

You really think that would be what's needed here?

 

[Snagglefoot]

https://www.spritmonitor.de/en/detail/1560000.html

and compared to other similar cars:

https://www.spritmonitor.de/en/over...2022&constyear_e=2026&power_s=114&power_e=124

You'll find I seem to have the best fuel consumption of the lot, and I'm running 10W-30 >3.5 HTHS oil

Umm, I was referring to what mileage as in how many 100 thousand miles they achieved.

 

[Snagglefoot]

You really think that would be what's needed here?

I was referring to ultimate mileage, not mpg. People are welcome to report how many miles they have on their 1.6 diesel and what oil they used.

The engine was introduced in the cruise in 2017 and the cruise was recently dropped, so basically it has 6-7 years in the Cruise platform. The engine was dropped from the Equinox AFAIK.

 

[kschachn]

I was referring to ultimate mileage, not mpg. People are welcome to report how many miles they have on their 1.6 diesel and what oil they used.

Differentiated by driving conditions, climate and condition variations and OCI of course.

 

[Bkdc]

The big question for me is — what is the lower range of temperature or kinematic viscosity that is SAFE (not most fuel efficient) to start revving the RPMs. I’m of the school that thicker is better to an extent unless the restricted flow is counterproductive.

The temperature at the upper cylinder/upper piston ring is much higher than the measured engine/coolant temperature so the area of most stress/wear is seeing much higher temperatures and more localized fuel dilution.

 

[Patman]

The big question for me is — what is the lower range of temperature or kinematic viscosity that is SAFE (not most fuel efficient) to start revving the RPMs. I’m of the school that thicker is better to an extent unless the restricted flow is counterproductive.

The temperature at the upper cylinder/upper piston ring is much higher than the measured engine/coolant temperature so the area of most stress/wear is seeing much higher temperatures and more localized fuel dilution.

On the cars that I have had that have oil temperature gauges I have a rule of thumb to wait until the oil hits 180F before going full throttle.

 

[burbguy82]

The engine oil in my 3.0L Duramax runs about 250F or 121C on the interstate. The 0w-20 would have a viscosity of about 5.9 cSt at that temperature. If my use was interstate all the time I would run HPL 15w-40 CC and get a viscosity of about 9.0 cSt, which is approximately the same viscosity as a 20wt at 100C.

so what are you saying here? 40 and 20 are the same?