Oil temperature?

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257
Location
NC
Does it make a real difference if one oil runs at a lower temperature in your engine compared to another? For example, if say when you use Mobil 1 in your car and during typical driving, the oil temp reads 230F, and then you switch to say a Pennzoil product and your oil temperature reads consistently lower, like 210F. What does that really mean? Is the Pennzoil product better for your car because it operates at a lower temp? Does it mean your engine will wear less or the oil will last longer?
 
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12,925
Location
Northern Kentucky
Is this a real scenario or mock? Are both oils the same viscosity grade? Usually the thinner oil will cool better so the cooler one might be formulated on the lower end of the viscosity range.
 
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10,146
Location
Burlington, Ontario, Canada
Well for starters I've never found an oil brand of the same viscosity made any significant difference to bulk sump oil temp's. There are so many other factors that do such as ambient temp's at the road surface so I wouldn't conclude that Pennzoil allows the engine to run cooler than M1. To your question on engine life, you haven't said what grade you're running not that 230F is all that hot, but it's certainly not an issue for a typical 5W-30 grade.
 
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726
Location
NoVA
Mine does the same...2 MPG better and it runs noticeably cooler. Lower friction with Pennzoil yellow bottle 10w30 than with others.
 
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14,505
Location
Top of Virginia
Originally Posted By: Lex94
Mine does the same...2 MPG better and it runs noticeably cooler..
What runs noticeably cooler (the engine coolant or the motor oil), and how are you measuring that?
 
Messages
553
Location
Phila, PA
This is something I noticed myself 1st hand. 2003 Z06 w/oil temp reading on driver information center. Originally with Mobil 1 5w-30, like clockwork I saw 217 degrees on my way home from work. Years ago, I changed to Amsoil 0w-30 Series 2000 oil and same drive, oil temps were now 199 degrees. Ran Mobil 1 M1-107 oil filter in both above OCI. Now I am currently running Amsoil 5w-30 Signature Series and see around 204 degrees or so as my common temp. Of course if I push it hard or drive it differently the temps also change, but I am comparing my normal run that is consistent that get driven daily. Is the lower temp better? Is the oil lubricating better? I know one thing, 217 is more likely to burn off moisture in the oil than 199. That is the only negative that I see with lower temps.
 
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Messages
553
Location
Toronto, Canada
All things being equal: ambient temps, viscosity grade down to the same cST, same oil filter, same engine run time & load then technically an oil that runs at a lower temp is better because it means less friction. But there are so many variables that affect oil temp, it's almost impossible to isolate friction from everything else.
 
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2,035
Location
Ontario, Canada
Any oil, any brand, that produces a drop in oil temperature is the one you want to choose IMO Even with a majority correlation in uncontrolled circumstances, is good enough to choose the 'cooler' oil.
 
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17,230
Location
Upper Midwest
So you really believe that the coefficient of friction is so much lower, and results in such lower friction induced heat that the temperature gauge would actually show a difference? Where does the thermostat come into play? Why doesn't it regulate around the setpoint? If the engine is really cooling more efficiently why doesn't the thermostat open more and warm it up? I'll play my hand here and say that no one, ever, is going to convince me that you could see the difference. The heat transfer between the coolant and the block/head is where the vast majority of the cooling takes place. Besides, any cooling the oil performs has to be rejected at the pan, right? Or on some cooler interior surface (but where do you find that?)
 
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8,859
Location
Texas
Originally Posted By: kschachn
I'll play my hand here and say that no one, ever, is going to convince me that you could see the difference. The heat transfer between the coolant and the block/head is where the vast majority of the cooling takes place. Besides, any cooling the oil performs has to be rejected at the pan, right? Or on some cooler interior surface (but where do you find that?)
I agree you'll never see a variation on the gauge that you can quantifiably attribute to oil brand. Too many other issues clouding things- for example, many modern engines have oil/coolant heat exchangers which *warm* the oil under light loading or very cold ambient temps, and cool the oil under heavy loading. There's a Chrysler video about the Pentastar out there that specifically mentions that the heat exchanger works toward a minimum 190F oil temperature for additive activation and to drive out condensates. Anything below 190F oil temp, and the oil "cooler" is actually serving as an oil heater. Its going to do that regardless of brand or weight, even if there were a difference in the way a heavier vs. thinner oil carried heat away from the hot spots (eg., piston undersides) to the sump, it would be overwhelmed by the cooling system trying to maintain a desired range of operation. And if you think there's enough FRICTION in the engine for a different brand of oil to make a measurable difference in oil temperature, then your engine has a serious problem! The oil has a >1000F heat source right above the piston crowns trying to warm it, and (possibly) various coolers trying to cool it or warm it depending on conditions. It would take a LOT of energy loss to friction to show up against that kind of background- enough that destruction would ensue quickly.
 
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1,445
Location
Dana Point, CA
Originally Posted By: 440Magnum
..And if you think there's enough FRICTION in the engine for a different brand of oil to make a measurable difference...
Nonsense! wink At least one contributor in this thread reduced fuel consumption by 2 MPG merely changing his motor oil.
 
Messages
43,667
Location
'Stralia
Originally Posted By: kschachn
I'll play my hand here and say that no one, ever, is going to convince me that you could see the difference. The heat transfer between the coolant and the block/head is where the vast majority of the cooling takes place. Besides, any cooling the oil performs has to be rejected at the pan, right? Or on some cooler interior surface (but where do you find that?)
I sort of agreed until recently, but my experiments prove otherwise. Logically, the hottest oil in the engine is that coming out the big end bearings, second hottest the mains...these are the locations where the engine is actively working against the oil, shearing it, a couple of hundreds of watts per bearing at 3-4k RPM. That oil drops back into the sump, having made no contact with cooled surfaces...that which does little to no work anyway, is, as you say cooled/warmed by running down water cooled/heated surfaces. Dropping a type K thermocouple down my disptick, directly between the high/low mark, my Caprice regularly reads 105-110C,and if I run 5 minutes at 4K revs, will read 120-125c...in ambients of -2 to 5C, well above coolant temperature. Push the thermocouple lower in the pan (Caprice has a big winged alloy pan), the oil temperature drops rapidly..an oil temperature sender closer to the pan wall will give a temperature closer to the pan temperature than what's leaving the bearings...perfect indicator of bearing supply temperature, but no correlation whatsoever on the working temperature in the bearings, which is determined by specific load, and RPM, and will be 10-20(+) C higher than the bulk oil temperatures.
 
Messages
43,667
Location
'Stralia
Originally Posted By: splinter
Originally Posted By: 440Magnum
..And if you think there's enough FRICTION in the engine for a different brand of oil to make a measurable difference...
Nonsense! wink At least one contributor in this thread reduced fuel consumption by 2 MPG merely changing his motor oil.
Extreme example to get extreme results http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3464122/Re:_Aviation's_Version_of_Mobi#Post3464122
 
Messages
1,313
Location
Alaska
Originally Posted By: zfasts03
Another easy way to check oil temp. is with a Raytec, non-contact thermometer on the bottom of the oil pan. I use this on my items without oil temp gauges. http://www.amazon.com/Raytek-MT4-Non-Con...keywords=raytec
How accurate is that going to be when the oil pan absorbs heat from the block? Not to mention aluminum and steel pans....I just can't see that telling you oil temp accurately.
 
Messages
726
Location
NoVA
Pennzoil yellow bottle 10w30, PUP 10w30, Quaker State green bottle 5w20 have all been outstanding...just give them a try.
 
Messages
43,667
Location
'Stralia
Originally Posted By: jayg
Originally Posted By: zfasts03
Another easy way to check oil temp. is with a Raytec, non-contact thermometer on the bottom of the oil pan.
How accurate is that going to be when the oil pan absorbs heat from the block? Not to mention aluminum and steel pans....I just can't see that telling you oil temp accurately.
I've got an IR coming, and will compare when it gets here...thermocouple measures a 15C gradient from top of oil to bottom, pan temp will be lower still. Discussion here
 

kjbock

Thread starter
Messages
257
Location
NC
Originally Posted By: 901Memphis
Is this a real scenario or mock? Are both oils the same viscosity grade? Usually the thinner oil will cool better so the cooler one might be formulated on the lower end of the viscosity range.
It was a mock scenario. But as a real example, on another BMW forum, a member claimed a 20F drop switching from Mobil 1 0W-40 to a Castrol 0W-40.
 
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