Max oil temps and myths?

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Sorry guys, didn't really know where to put this one, I was lying awake last night with a nasty cold and cough so no sleep.... This weekend I got my deep fryer out and made a big batch of hot wings and as usual, I get my oil (Canola) up to 350-375*F before dropping my wings in... this got me to thinking why does everyone in the automotive world panic when the oils temps exceed 250*F?? It doesn't seem to phase this cheap canola oil and I know the high quality base oils used in all major suppliers of PCMO's and HDEO's has to better than this cooking oil, right?? Case in point- my 2005 Ford F350 with the 6.0 diesel engine. These are known to have oil cooler issues and folks on the forums as well as OE Ford TB's say oil temps in excess of 250* is BAD!! Why are we so concerned with what seems to be a relatively mild oil temp in cars? Especially if we're running a quality synthetic? Does 250-300* actually hurt todays oils?
 
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Problem is, where are you measuring the temperature? The sump is one temp, the oil in the heads another. The temperature in the bearings is yet another, and then there is the oil temp on the cylinder walls and in the drain holes in the pistons. If I'm not mistaken, the temperature of oil in a deep fryer is a relative constant, hotter near the heat source I'm sure, but I am thinking it does not have the wild swings that an engine would have. I wonder how long oil in a deep fryer is good for? contrasted against engine hours.
 
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Oil in my NSX goes gets hot, I tend to shut it down at about 275F on track, but I've run hotter when having fun. I've emailed Red Line and they said that wasn't a problem. Pressures remain fine, OUA comes back fine. I also talked to Mobil 1, who told me they would set 300F as a "conservative limit". <shrug>
 
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Great Lakes
Originally Posted by racin4ds
Sorry guys, didn't really know where to put this one, I was lying awake last night with a nasty cold and cough so no sleep.... This weekend I got my deep fryer out and made a big batch of hot wings and as usual, I get my oil (Canola) up to 350-375*F before dropping my wings in... this got me to thinking why does everyone in the automotive world panic when the oils temps exceed 250*F?? It doesn't seem to phase this cheap canola oil and I know the high quality base oils used in all major suppliers of PCMO's and HDEO's has to better than this cooking oil, right??
Apples to oranges, I'm afraid. Canola is a much simpler fluid, not loaded with VIIs and additives that may not handle temperature extremes as well. Then there is the time component - is your Canola good for 300 hours of being in service and providing the necessary film strength between moving metal parts? Maybe we should all just start using Canola in our engines because it's so good. smile And Delo sucks - fried wings don't taste as good after being fried in it. smile
 
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Oil temps are a sensitive subject to some. I personally don't care if the oil gets up there so long as there's a reason for it (I'm towing up a steep incline or racing, for example), and I know the oil can take it. I'm a drag racer so engine oil temp isn't an issue for me. The real issue for me is trans temperature. It kills me when people don't monitor trans fluid temp when using a transbrake. The ATF climbs +50-60*F per second while on the transbrake and some guys will sit there 5+ seconds trying to build boost or something and melting the trans in the process.
 
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Atlanta,GA
Originally Posted by racin4ds
Sorry guys, didn't really know where to put this one, I was lying awake last night with a nasty cold and cough so no sleep.... This weekend I got my deep fryer out and made a big batch of hot wings and as usual, I get my oil (Canola) up to 350-375*F before dropping my wings in... this got me to thinking why does everyone in the automotive world panic when the oils temps exceed 250*F?? It doesn't seem to phase this cheap canola oil and I know the high quality base oils used in all major suppliers of PCMO's and HDEO's has to better than this cooking oil, right?? Case in point- my 2005 Ford F350 with the 6.0 diesel engine. These are known to have oil cooler issues and folks on the forums as well as OE Ford TB's say oil temps in excess of 250* is BAD!! Why are we so concerned with what seems to be a relatively mild oil temp in cars? Especially if we're running a quality synthetic? Does 250-300* actually hurt todays oils?
Apples to oranges. The canola oil in your deep fryer is oxidizing as well. 10-15 mins in a deep fryer is not comparable to what goes on inside an ICE.
 
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LOL all interesting and good responses.... sorry for the late night thoughts... large doses of cold meds and no sleep causes weird randomness... smile My deep fryer has a good fitting lid and I do use the same oil many many times before replacing, I usually go by how dark it has gotten and how it smells... if it is oxidizing and evaporating, it isn't much though because it has a clear line that states "MAX" and I don't add often... smile I'm thinking when I retire this fry daddy I'll take it to the shop for some youTube oil testing and see what happens! sounds like a better way to spend my sleepless nights..... smile
 
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California
Motor oil has much more to handle besides high temperatures. Motor oil has to clean, lubricate, suspend particulates, combat sludge, neutralize acids, resist shearing forces, flow well at very low temperatures, etc. Lots of demands. I agree with the statement about oil temperature being much higher on the surface of some internal engine parts, particularly the underside of pistons. This brief but very high temperature is not reflected by the oil temperature gauge.
 
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pa
for starters your KILLING yourself with canola aka rapseed oil a seed oil NOT a vegetable oil, search + learn Dr Ken D Berry, your choice! the wings real fat ate NOT as bad as they want us to believe as its the carbs that quickly turn to SUGAR thats the culprit!! now about engine oils + the heat they occur + the THINNING that takes place from high heat, check out savage geese OIL the fine print, he notes even the best oils like Redline that are TOO thin do NOT protect an engine properly!!
 
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Austin Texas
High temperatures means lower viscosity. At some point the viscosity becomes too low to support the loads. There is an oil temperature gauge in my "sports car" that has a red line marked within spitting distance of 305ºF. The Factory oil at the time of manufacture was Shell Helix 5W-40 that had an HTHS of 4.2 cP in 1999, when I started paying attention. HTHS is measured at 150ºC which happens to be 302ºF which happens to be the same as the red line on the temperature gauge. I take this to mean the factory does not want you to use the engine hard when the oil viscosity is lower than 4.2cP. And with a red line above 8,500 RPMs in a flat plane crank V8, it can be used quite hard indeed. Note: It is almost impossible to get the oil temperature above 250°F with extremely spirited back road driving, there is an oil air heat exchanger 1/2 as large as the engine water air radiator and dry sump. And the only times I have seen the oil temperature above 250ºF is on race tracks at HPDE events. One of the things that always amazed me is that after a track event, the oil pressure gauge would always show a 5 PSI decrease in the oil pressure until the oil was changed at which time the oil pressure returned to 70 PSI at 3,000 RPMs and above. Even at race tracks, the car consumed no oil over a OCI.
 
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WA
Originally Posted by racin4ds
Case in point- my 2005 Ford F350 with the 6.0 diesel engine. These are known to have oil cooler issues and folks on the forums as well as OE Ford TB's say oil temps in excess of 250* is BAD!! Why are we so concerned with what seems to be a relatively mild oil temp in cars? Especially if we're running a quality synthetic? Does 250-300* actually hurt todays oils?
OP... The Arrhenius rate rule says the rate of oxidation for a lubricant doubles for every +18f increase above operating temp. Machinery Lubrication Petroleum Service Co. [Linked Image]
 
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IL
If the fries are not coming out with a golden brown color, it's time to change your oil. We have all been to restaurants that should have changed the fryer oil last night....
 
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Arizona
Oil temperatures are nothing to be concerned about unless you race for long periods, or tow things up mountains in a gasoline vehicle you wouldn't usually see being used for such work lol. That's when you probably want to bump up oil viscosity to maintain oil pressure. Performance vehicles usually spec a thicker oil anyway to maintain viscosity at temperatures above 250° F. Sometimes not, like the LS1 engines. They are recommended 5w-30 in the US just for better gas mileage. Racing one? You want like a 15w-40 in there.
 
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South Carolina
250 Degrees is a non issue with motor oil Above 265 you will start shortening its life for sure. With all that said, manufacturers spec oil weight on expected running oil temperatures of the particular engine. I dont think I would want a 5/20 oil at those temperatures or possibly even a 5/30 weight as they will be quite thin at those temps. (just my thoughts)
 
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Waco, TX
Some engines see accelerated wear at certain locations with very high oil temps. Some distributor shaft bushings (and distributor gear/cam gear) life goes down pretty fast with very hot oil. Very hot oil can also reduce the life of certain plastic/nylon parts in the engine. Older GM engines would destroy the plastic timing chain cam gear when the oil got too hot.
 
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