oil weight versus cooling - hard data?

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The subject of oil weight versus cooling has been discussed quite a bit but I haven't been able to find any hard data. Theoretically, a thinner oil provides better cooling as long as it is thick enough to maintain sufficient hydrodynamic pressure to prevent boundary lubrication, right? (don't know if I said that right, but I hope the meaning is clear enough). Anyway, I was wondering if anyone knows of any measurements of engine temperature versus oil weight to prove or disprove the above notion, and to quantify the relationship. Thanks,
 
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I'd like to know some hard facts also. I feel that a thin 5w-30 or 0w-30 would cool better than the old 15w-40 favorite on this site. Even in hot weather.
 

ALS

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With my car a Volvo Turbo the oil stays 10 to 20 degree's cooler with synthetic over mineral. Was using Pennzoil 10W30 now using Mobil One 10W30. Before oil temps ran from 190 to 210 under normal driving conditions. With the Mobil One Synthetic the gauge almost never goes above 180 degree's. In the winter 160 to 165 degrees is the normal operating range.
 
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perhaps on some minute scale a thinner viscosity oil would provide better cooling, however i do not think it is enough to notice. my engine features duel oil squirters per piston, and i have never seen an oil temp difference between the various viscosity's of different oils, from 0w30 to straight 30 15w40 or even 20w50, the oil temp generally remains about 10c under the water temp which is 190c according to my water temp gauge. the actual physical cylinder head is usually 20c over the water temp.
 
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i haven't noticed any pattern on my vette at all, given the following oils: chevron supreme 10w30 schaeffer's #700 schaeffer's #151 royal purple 10w40 chevron delo 15w40 chevron delo sae30 castrol syntec 5w50 castrol syntec 0w30 (GC) mobil 1 5w30 shell rotella 5w40 -michael
 

MRC01

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quote:
Originally posted by cryptokid: the oil temp generally remains about 10c under the water temp which is 190c according to my water temp gauge. the actual physical cylinder head is usually 20c over the water temp.
Your water temp is 190c = 374F ?!?! Your oil temp is 180c = 356F ?!?! Are you sure? What kind of engine is that?
 
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quote:
Originally posted by MRC01:
quote:
Originally posted by cryptokid: the oil temp generally remains about 10c under the water temp which is 190c according to my water temp gauge. the actual physical cylinder head is usually 20c over the water temp.
Your water temp is 190c = 374F ?!?! Your oil temp is 180c = 356F ?!?! Are you sure? What kind of engine is that?

A very, very hot one. . . [Big Grin] Seriously though, I just assumed he had mistakenly typed "c" when he meant "F".
 

MRC01

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quote:
Originally posted by ekpolk:
quote:
Originally posted by MRC01:
quote:
Originally posted by cryptokid: [qb]the oil temp generally remains about 10c under the water temp which is 190c according to my water temp gauge. the actual physical cylinder head is usually 20c over the water temp.

Your water temp is 190c = 374F ?!?! Your oil temp is 180c = 356F ?!?!
A very, very hot one. . . [Big Grin] Seriously though, I just assumed he had mistakenly typed "c" when he meant "F".

I thought so too. But isn't 180* F rather cool for full operating oil temp? Seems like that might not even be hot enough to burn off water contamination in the oil... I figured "normal" oil temps would be in the low 200* F range. But I dunno, maybe I'm wrong. If the coolant is around 190* F, which seems about right, that would mean the oil would be about 20* F warmer than the coolant. Is that about right?
 
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[/QUOTE]I thought so too. But isn't 180* F rather cool for full operating oil temp? Seems like that might not even be hot enough to burn off water contamination in the oil... I figured "normal" oil temps would be in the low 200* F range. But I dunno, maybe I'm wrong. If the coolant is around 190* F, which seems about right, that would mean the oil would be about 20* F warmer than the coolant. Is that about right? [/QB][/QUOTE] I would think the temperature of the oil hiting the bottom of the piston would turn the water into steam and then out the breather or PCV. Average temp in the oil pan may stay 180 even so.
 

Patman

Staff member
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quote:
Originally posted by Michael SR: i haven't noticed any pattern on my vette at all, given the following oils: chevron supreme 10w30 schaeffer's #700 schaeffer's #151 royal purple 10w40 chevron delo 15w40 chevron delo sae30 castrol syntec 5w50 castrol syntec 0w30 (GC) mobil 1 5w30 shell rotella 5w40 -michael
Wow, and I thought I tried a lot of different oils! [bowdown]
 
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But, aren't oil temperatures widely varied....ie. you have the mean oil temperature and then you have oil temperatures in areas directly involved with combustion/piston surfaces, valve stems, etc...
 

MRC01

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Excellent point. So nobody has any hard data or reference material for oil weight versus cooling / temperature? I've searched both this site and the internet to no avail.
 
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