I think the common-sense answers here apply very well, such as 1sttruck's comments about the obvious temp differences you notice any time you open the hood. No doubt modern cooling systems and in some cases thermostatically-controlled oil coolers moderate the oil temps but there is still no doubt a good deal of variance.
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How does high ambient temperature affect oil ?
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Originally Posted By: BuickGN
Originally Posted By: jpr
couple of questions for the gallery:
* Does anybody consider an '84 Buick to be modern car?
* Does anybody believe there is no correllation amonf engine temperature, coolant temperature, and oil temperature?
You're right, the "old" cars don't follow the laws of physics. My observations are invalid because my car was made in 1984.
There may be some correlation between coolant temps and oil temps but in my experience with a constant 165 degree water temp, oil still runs 195-220 degress regardless.
It's not the laws of physics genius, it's the practice of engineering.
Do you suppose if your water temp ran at say, 135 or 195, your oil temps might be different as well?
Originally Posted By: jpr
couple of questions for the gallery:
* Does anybody consider an '84 Buick to be modern car?
* Does anybody believe there is no correllation amonf engine temperature, coolant temperature, and oil temperature?
You're right, the "old" cars don't follow the laws of physics. My observations are invalid because my car was made in 1984.
There may be some correlation between coolant temps and oil temps but in my experience with a constant 165 degree water temp, oil still runs 195-220 degress regardless.
It's not the laws of physics genius, it's the practice of engineering.
Do you suppose if your water temp ran at say, 135 or 195, your oil temps might be different as well?
Last edited:
Originally Posted By: glennc
I think the common-sense answers here apply very well, such as 1sttruck's comments about the obvious temp differences you notice any time you open the hood. No doubt modern cooling systems and in some cases thermostatically-controlled oil coolers moderate the oil temps but there is still no doubt a good deal of variance.
...
Originally Posted By: jpr
I have no doubt that oil temps vary a bit. The big question though, is does it vary enough to care about it? For modern cars, I'd guess "no" for 99% of the cases.
I think the common-sense answers here apply very well, such as 1sttruck's comments about the obvious temp differences you notice any time you open the hood. No doubt modern cooling systems and in some cases thermostatically-controlled oil coolers moderate the oil temps but there is still no doubt a good deal of variance.
...
Originally Posted By: jpr
I have no doubt that oil temps vary a bit. The big question though, is does it vary enough to care about it? For modern cars, I'd guess "no" for 99% of the cases.
Last edited:
Originally Posted By: jpr
Originally Posted By: BuickGN
Originally Posted By: jpr
couple of questions for the gallery:
* Does anybody consider an '84 Buick to be modern car?
* Does anybody believe there is no correllation amonf engine temperature, coolant temperature, and oil temperature?
You're right, the "old" cars don't follow the laws of physics. My observations are invalid because my car was made in 1984.
There may be some correlation between coolant temps and oil temps but in my experience with a constant 165 degree water temp, oil still runs 195-220 degress regardless.
It's not the laws of physics genius, it's the practice of engineering.
Do you suppose if your water temp ran at say, 135 or 195, your oil temps might be different as well?
The topic of this thread had nothing to do with modern cars, genius. You asked the sarcastic question "Does anybody consider an '84 Buick to be a modern car?" and you got a sarcastic answer.
You seem to have an agenda even though several people with oil temp guages have answered the question already. My coolant temp is on the cool side and still my oil runs at what's considered normal temps and it varies with ambient temps and load.
Off topic but when I used Total Seal gapless rings on this engine, oil temps consistantly run lower.
Originally Posted By: BuickGN
Originally Posted By: jpr
couple of questions for the gallery:
* Does anybody consider an '84 Buick to be modern car?
* Does anybody believe there is no correllation amonf engine temperature, coolant temperature, and oil temperature?
You're right, the "old" cars don't follow the laws of physics. My observations are invalid because my car was made in 1984.
There may be some correlation between coolant temps and oil temps but in my experience with a constant 165 degree water temp, oil still runs 195-220 degress regardless.
It's not the laws of physics genius, it's the practice of engineering.
Do you suppose if your water temp ran at say, 135 or 195, your oil temps might be different as well?
The topic of this thread had nothing to do with modern cars, genius. You asked the sarcastic question "Does anybody consider an '84 Buick to be a modern car?" and you got a sarcastic answer.
You seem to have an agenda even though several people with oil temp guages have answered the question already. My coolant temp is on the cool side and still my oil runs at what's considered normal temps and it varies with ambient temps and load.
Off topic but when I used Total Seal gapless rings on this engine, oil temps consistantly run lower.
Originally Posted By: BuickGN
Originally Posted By: jpr
Originally Posted By: BuickGN
Originally Posted By: jpr
couple of questions for the gallery:
* Does anybody consider an '84 Buick to be modern car?
* Does anybody believe there is no correllation amonf engine temperature, coolant temperature, and oil temperature?
You're right, the "old" cars don't follow the laws of physics. My observations are invalid because my car was made in 1984.
There may be some correlation between coolant temps and oil temps but in my experience with a constant 165 degree water temp, oil still runs 195-220 degress regardless.
It's not the laws of physics genius, it's the practice of engineering.
Do you suppose if your water temp ran at say, 135 or 195, your oil temps might be different as well?
The topic of this thread had nothing to do with modern cars, genius. You asked the sarcastic question "Does anybody consider an '84 Buick to be a modern car?" and you got a sarcastic answer.
You seem to have an agenda even though several people with oil temp guages have answered the question already. My coolant temp is on the cool side and still my oil runs at what's considered normal temps and it varies with ambient temps and load.
Off topic but when I used Total Seal gapless rings on this engine, oil temps consistantly run lower.
Agenda? What a silly idea.
And BTW, I think you just made my point for me - regardless of ambient temperature, your oil still stays within a temperature considered "normal."
And that's with an engine designed some 20+ years ago. Surely you don't think modern engines are more sensitive to ambient temps and have a harder time keeping the oil in a normal temperature range?
Originally Posted By: jpr
Originally Posted By: BuickGN
Originally Posted By: jpr
couple of questions for the gallery:
* Does anybody consider an '84 Buick to be modern car?
* Does anybody believe there is no correllation amonf engine temperature, coolant temperature, and oil temperature?
You're right, the "old" cars don't follow the laws of physics. My observations are invalid because my car was made in 1984.
There may be some correlation between coolant temps and oil temps but in my experience with a constant 165 degree water temp, oil still runs 195-220 degress regardless.
It's not the laws of physics genius, it's the practice of engineering.
Do you suppose if your water temp ran at say, 135 or 195, your oil temps might be different as well?
The topic of this thread had nothing to do with modern cars, genius. You asked the sarcastic question "Does anybody consider an '84 Buick to be a modern car?" and you got a sarcastic answer.
You seem to have an agenda even though several people with oil temp guages have answered the question already. My coolant temp is on the cool side and still my oil runs at what's considered normal temps and it varies with ambient temps and load.
Off topic but when I used Total Seal gapless rings on this engine, oil temps consistantly run lower.
Agenda? What a silly idea.
And BTW, I think you just made my point for me - regardless of ambient temperature, your oil still stays within a temperature considered "normal."
And that's with an engine designed some 20+ years ago. Surely you don't think modern engines are more sensitive to ambient temps and have a harder time keeping the oil in a normal temperature range?
One contributor to sludging seems to be high engine temps somewhere in the engine. If you drink lots of Japanese car Koolaid you can whine about people not changing their oil, but that happens with most vehicles and still only some modern vehicles exhibit the problem to such a degree to make list of 'sludgers'. It's safe to assume that most vehicles will be designed and operated so that the cooling system operates within normal temperature ranges, but the sludging problem suggests that the same can't be said for oil temperatures everywhere in the engine.
Of course it's in a normal range but it varies roughly 30 degrees from winter to summer.
One point to bring up is that when driven hard, oil temps seem to climb quicker in the summer.
In this particular car I'm usually only on the gas for a few seconds and always give it time to cool between runs because it is a small displacement motor with a decent amount of power and it will put a ton of heat into the oil quickly.
One point to bring up is that when driven hard, oil temps seem to climb quicker in the summer.
In this particular car I'm usually only on the gas for a few seconds and always give it time to cool between runs because it is a small displacement motor with a decent amount of power and it will put a ton of heat into the oil quickly.
The past bears fruit here:
https://bobistheoilguy.com/forums/posts/729229/
Quote:
An interesting side-bar of the study was that the bulk oil temperature increased "only" 0.3 C for every 1.0 C increase in ambient (oustside) temperatures.
https://bobistheoilguy.com/forums/posts/729229/
Quote:
An interesting side-bar of the study was that the bulk oil temperature increased "only" 0.3 C for every 1.0 C increase in ambient (oustside) temperatures.
Hey lookee - here's some tech info courtesy of Molakule - https://bobistheoilguy.com/forums/threads/sump-oil-vs-coolant-temperatures.57851/
Quote:
The predicted sump (bulk) oil temperature versus the coolant temperature was shown to be about 18 to 20 degrees C higher for the oil than for the coolant at 2,000 RPM WOT. At 4,000 RPM WOT, the oil sump temperature was about 50 degrees C higher than the coolant temperature. The slope for both RPM ranges was about 0.7 C/C, which means that on the average, the Oil Sump temperature is always 1.2 to 1.43 times higher than the coolant temp.
An interesting side-bar of the study was that the bulk oil temperature increased "only" 0.3 C for every 1.0 C increase in ambient (oustside) temperatures.
EDIT - ah, I see JAG is quicker on the keyboard than I
Quote:
The predicted sump (bulk) oil temperature versus the coolant temperature was shown to be about 18 to 20 degrees C higher for the oil than for the coolant at 2,000 RPM WOT. At 4,000 RPM WOT, the oil sump temperature was about 50 degrees C higher than the coolant temperature. The slope for both RPM ranges was about 0.7 C/C, which means that on the average, the Oil Sump temperature is always 1.2 to 1.43 times higher than the coolant temp.
An interesting side-bar of the study was that the bulk oil temperature increased "only" 0.3 C for every 1.0 C increase in ambient (oustside) temperatures.
EDIT - ah, I see JAG is quicker on the keyboard than I
Last edited:
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I'd say that load effects oil temp more than ambient temp in my experience. Time to temp was about the same too. Even with single digit starting temps. This assumes that you run the thing long enough. I tracked this var-ree care-fooly. That is, a radically cooler starting temp merely stretched the time/mileage to temp maby 30 seconds or so at highway speeds. It still took about 13+ miles to reach the peak normalized temp. The minivan empty would peak out somewhere around 215F with just me in it @ 70mph. With 5 people in it it would be 220F.
Naturally, YOTMV.
Naturally, YOTMV.
Winter and Summer - 40deg F or so difference in running oil temp.
FWIW - here's an example of oil temp differential due to high ambient temperature using the SAE formula described above:
77 Deg F = 25 Deg C
113 Deg F = 45 Deg C
Ambient Temp difference = 36 Deg F = 20 Deg C
Expected Bulk Oil Temp difference due to change in ambient temperature = 10.8 deg F = 6 Deg C
77 Deg F = 25 Deg C
113 Deg F = 45 Deg C
Ambient Temp difference = 36 Deg F = 20 Deg C
Expected Bulk Oil Temp difference due to change in ambient temperature = 10.8 deg F = 6 Deg C
Originally Posted By: jpr
FWIW - here's an example of oil temp differential due to high ambient temperature using the SAE formula described above:
77 Deg F = 25 Deg C
113 Deg F = 45 Deg C
Ambient Temp difference = 36 Deg F = 20 Deg C
Expected Bulk Oil Temp difference due to change in ambient temperature = 10.8 deg F = 6 Deg C
You forgot to also includes the heating effects of air conditioning, since the use of an air conditioner will generally increase with ambient temperature and will cause additional engine oil heating. The use of the AC causes overheating frequently in area of the southwest such as Arizona (over 120F ambience during the summer). If the coolant is overheated then what do you think the oil temperature will be?
FWIW - here's an example of oil temp differential due to high ambient temperature using the SAE formula described above:
77 Deg F = 25 Deg C
113 Deg F = 45 Deg C
Ambient Temp difference = 36 Deg F = 20 Deg C
Expected Bulk Oil Temp difference due to change in ambient temperature = 10.8 deg F = 6 Deg C
You forgot to also includes the heating effects of air conditioning, since the use of an air conditioner will generally increase with ambient temperature and will cause additional engine oil heating. The use of the AC causes overheating frequently in area of the southwest such as Arizona (over 120F ambience during the summer). If the coolant is overheated then what do you think the oil temperature will be?
As noted earlier, the formula is not mine, it is from the SAE study. You will need to take your question up with the authors.
I can see increased load on the engine as a result of having to drive the A/C system, but you seem to stating that the engine radiator and A/C condenser share coolant?
I can see increased load on the engine as a result of having to drive the A/C system, but you seem to stating that the engine radiator and A/C condenser share coolant?
I hot weather, particularly in stop and gop traffic, coolant temperature often rises well above the thermostat set point.
An AC condenser puts additional heat into the already hot air that's going through the radiator, so although they don't share coolant, they are thermally coupled.
An AC condenser puts additional heat into the already hot air that's going through the radiator, so although they don't share coolant, they are thermally coupled.
Originally Posted By: jpr
I can see increased load on the engine as a result of having to drive the A/C system, but you seem to stating that the engine radiator and A/C condenser share coolant?
There is no such thing as a car engine sharing coolant between the radiator and the A/C condenser. The A/C system generates so much heat that it will overwhelm the engine cooling system because the A/C dumps that heat directly into the radiator. The condenser sits in front of the radiator in most if not all vehicles. The heat from the A/C and the radiator then get pushed onto the engine. The oil temperature in my Excursion PSD reaches 140 deg C on occasion when I tow my RV while coolant temp is less than 80 deg C. Part of the reason is the oil cooled turbo that see 1200-1600 deg F often.
I can see increased load on the engine as a result of having to drive the A/C system, but you seem to stating that the engine radiator and A/C condenser share coolant?
There is no such thing as a car engine sharing coolant between the radiator and the A/C condenser. The A/C system generates so much heat that it will overwhelm the engine cooling system because the A/C dumps that heat directly into the radiator. The condenser sits in front of the radiator in most if not all vehicles. The heat from the A/C and the radiator then get pushed onto the engine. The oil temperature in my Excursion PSD reaches 140 deg C on occasion when I tow my RV while coolant temp is less than 80 deg C. Part of the reason is the oil cooled turbo that see 1200-1600 deg F often.
az - Nice to know you're not totally out to lunch
xs650 - stop and go is nasty on engine temp because the only airflow is from the fan. Same way your brakes get hotter after you stop driving.
xs650 - stop and go is nasty on engine temp because the only airflow is from the fan. Same way your brakes get hotter after you stop driving.
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