Oil getting hot quickly

[Meep]

Yeah, I started to realize that these temps are quite normal when it comes to these engines. I drove pretty hard this past weekend and the temps on the oil actually went down a bit, probably from the cooling kicking in. I never really went above 106-107 C (220-225 F).
Although I can see my exhaust temps can go up to 850-870 C (1500-1600 F) for some instances, but then rapidly drop in temps as soon as you dont push it anymore.

Although what I also was wondering were if anyone that had switch from the factory 0W20 to 5W30 (or similar) would see cooler temperatures overall.

I switched to 5w30 recently, Temps stay the same

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[Evolution]

Thicker oil tends to raise oil temps if the cooling system isnt up to the task.

 

[OneTimeAccount]

Thicker oil tends to raise oil temps if the cooling system isnt up to the task.

Interesting.

I was at a track day at GingerMan a couple weeks ago, temp was around 50-55 degrees Fahrenheit outside, and my logs showed oil temps going to 237F max after a few hot laps. I assume that’s well within operating range when at the track. I’m using Liqui Moly 5w30. Departing going back to Liqui Moly 0w20.

Coolant temps were around 194F at all times.

 

[Evolution]

Interesting.

I was at a track day at GingerMan a couple weeks ago, temp was around 50-55 degrees Fahrenheit outside, and my logs showed oil temps going to 237F max after a few hot laps. I assume that’s well within operating range when at the track. I’m using Liqui Moly 5w30. Departing going back to Liqui Moly 0w20.

Coolant temps were around 194F at all times.

We wont get in to the great oil debate but the facts are thicker oil gets hotter than thin because it does a better job of removing heat from all the components.

Again, if the oil cooling system is up to the task, oil temps will stay the same, within their regulated temps.

 

[Tri5tate]

So, for a final answer - if the temps stay within 200-260 F (mine has never gone over 235), then should I even care to switch to 5W30? Im running a stage 1 tune at 440hp, and all the time people say that I should switch to a thicker oil because the 0W20 is too thin and will shorten the life of the engine.
Is the temperature all you should care about?

It seems like there will always be a debate wether one can be fine using 0W20 or must switch to a thicker oil

 

[Evolution]

So, for a final answer - if the temps stay within 200-260 F (mine has never gone over 235), then should I even care to switch to 5W30? Im running a stage 1 tune at 440hp, and all the time people say that I should switch to a thicker oil because the 0W20 is too thin and will shorten the life of the engine.
Is the temperature all you should care about?

It seems like there will always be a debate wether one can be fine using 0W20 or must switch to a thicker oil

Oh man if you are running a stage 1 tune you need some straight 100 weight! I kid I kid...

My personal opinion is that 0w-20 is not for track use. 5w-30 really isnt either but its better. Oil has 2 main goals, to keep metal from metal contact (load capacity rating) and heat transfer. The oil cools all the components and the oil cooling system cools the oil. So if you are making more heat than normal (racing) you want an oil that can transfer the heat faster (thicker oil). Oil temp is definitely something to keep an eye on as the hotter oil gets, the faster it breaks down. Obviously, there is a lot more to it but thats the basics.

End of the day, its your car, run what you want as long as its a stage 1 rated oil

 

[puzzled]

I did my oil change today and was testing my Jb4 to make sure it was working and have an oil temp monitor on the screen.. within like 5 min the oil was 215F.. so I'm also a fat elephant with huge .. never mind.

 

[dzeleski]

We wont get in to the great oil debate but the facts are thicker oil gets hotter than thin because it does a better job of removing heat from all the components.

Again, if the oil cooling system is up to the task, oil temps will stay the same, within their regulated temps.

This isn’t true. Thicker oil can hold slightly more heat but it takes longer to do so because it moves slower. Thinner oil does hold slightly less heat but it is able to move that heat faster because it flows faster. Therefore thinner oil is better at moving heat from one place to another.

Thicker oil causes more friction and pressure within the engine which generates more heat. Which is why it runs hotter. It takes longer for the oil to go through the bearings, journals, etc. as well as takes more energy to do it (causing more heat). Which also means you can damage an engine by running the wrong weight oil, higher oil pressure is not always better because flow won’t be high enough and then the bypass valve opens dumping the extra.

If what you were saying was true we would be running much thicker coolant, but we do not because flow rate is more important.

https://blog.amsoil.com/what-happens-if-i-use-the-wrong-weight-viscosity-of-oil/amp/

https://www.verus-engineering.com/blog/informative-8/oil-cooling-a-deeper-look-29

 

[Evolution]

This isn’t true. Thicker oil can hold slightly more heat but it takes longer to do so because it moves slower. Thinner oil does hold slightly less heat but it is able to move that heat faster because it flows faster. Therefore thinner oil is better at moving heat from one place to another.

Thicker oil causes more friction and pressure within the engine which generates more heat. Which is why it runs hotter. It takes longer for the oil to go through the bearings, journals, etc. as well as takes more energy to do it (causing more heat). Which also means you can damage an engine by running the wrong weight oil, higher oil pressure is not always better because flow won’t be high enough and then the bypass valve opens dumping the extra.

If what you were saying was true we would be running much thicker coolant, but we do not because flow rate is more important.

https://blog.amsoil.com/what-happens-if-i-use-the-wrong-weight-viscosity-of-oil/amp/

https://www.verus-engineering.com/blog/informative-8/oil-cooling-a-deeper-look-29

Lol you are saying the same thing as me in a different way. I didnt want to get all technical but can if you would like. Heat is a byproduct of friction but more friction isn't technically a bad thing, to a point.

This is a perfect example of why an engines cooling system carries twice as much fluid as the oil pan and why the radiator is massive compared to the oils heat echanger. Thick fluid vs thin.

 

[dzeleski]

Lol you are saying the same thing as me in a different way. I didnt want to get all technical but can if you would like. Heat is a byproduct of friction but more friction isn't technically a bad thing, to a point.

This is a perfect example of why an engines cooling system carries twice as much fluid as the oil pan and why the radiator is massive compared to the oils heat echanger. Thick fluid vs thin.

No I’m not.

What you said and are still saying is wrong. Read the articles I posted, they completely and entirely refute what you are saying.

Oil is not the “primary” means of cooling on a water cooled engine which is why the system capacity is smaller(Oil is typically responsible for 30-40% of cooling, different applications can change this a bit but it generally stays below 50%). Oils primary purpose is lubrication and localized temp control of the bearing surfaces from pressure and shear, as well as the pistons from combustion. The coolants purpose is strictly to cool the engine, hence its heat capacity needs to be larger since it’s not only helping to cool the engine directly but also indirectly from cooling the oil. Coolant is able to transfer heat faster then oil can which is why coolant is typically used to also cool the oil.

You said “facts are thicker oil gets hotter than thin because it does a better job of removing heat from all the components.” Which is completely incorrect and violates physics. You can’t have higher temps in a closed system and have better cooling, that’s impossible. Thicker oil runs hotter because it can’t transfer heat as efficiently, as well as requiring more energy to pump throughout the engine. So no we are not saying the same thing at all. The fact that you think more friction isn’t a bad thing is where I stop even bothering to have this discussion.

 

[Evolution]

No I’m not.

What you said and are still saying is wrong. Read the articles I posted, they completely and entirely refute what you are saying.

Oil is not the “primary” means of cooling on a water cooled engine which is why the system capacity is smaller(Oil is typically responsible for 30-40% of cooling, different applications can change this a bit but it generally stays below 50%). Oils primary purpose is lubrication and localized temp control of the bearing surfaces from pressure and shear, as well as the pistons from combustion. The coolants purpose is strictly to cool the engine, hence its heat capacity needs to be larger since it’s not only helping to cool the engine directly but also indirectly from cooling the oil. Coolant is able to transfer heat faster then oil can which is why coolant is typically used to also cool the oil.

You said “facts are thicker oil gets hotter than thin because it does a better job of removing heat from all the components.” Which is completely incorrect and violates physics. You can’t have higher temps in a closed system and have better cooling, that’s impossible. Thicker oil runs hotter because it can’t transfer heat as efficiently, as well as requiring more energy to pump throughout the engine. So no we are not saying the same thing at all. The fact that you think more friction isn’t a bad thing is where I stop even bothering to have this discussion.

I was going to make this big long response but its not worth it. I made 2 things bold in your quote.

Surface temps are the main thing. So you said

Thinner oil does hold slightly less heat but it is able to move that heat faster because it flows faster.

Moves heat faster, yes but not as much heat. Example (using generic numbers here) - Say the bearing temp is 300 degrees, thin oil might only cool them 20 degrees. Thick oil would cool them say 40 degrees. Thats 20 extra degrees in the oils temp. That equates to hotter oil temps going in to the heat exchanger. If the heat exchanger is up to the task, it will spit out oil thats say 230 degrees regardless if the oil comes in at 280 or 260 degrees. This really comes into the equation when pressures and surface temps get high, as in racing.

Friction is a trade off when you think about it. Friction equals heat dissipation (or making heat if you want to put it that way). The longer the oil touches a surface, the longer it has time to transfer heat. Friction is also part of an oil having a higher load capacity. Obviously too much is a bad thing but when we are talking about going from a 0w-20 to a 5w-30, its not a huge difference. Going to a 20w-50 is a completely different story which is where different bearing clearances come in to play. Guess what? 0w-20 has less friction than thicker oils but it also has less of a load bearing capacity. Pick one side. I actually race my car so I chose the less efficient side.

 

[dzeleski]

I was going to make this big long response but its not worth it. I made 2 things bold in your quote.

Surface temps are the main thing. So you said



Moves heat faster, yes but not as much heat. Example (using generic numbers here) - Say the bearing temp is 300 degrees, thin oil might only cool them 20 degrees. Thick oil would cool them say 40 degrees. Thats 20 extra degrees in the oils temp. That equates to hotter oil temps going in to the heat exchanger. If the heat exchanger is up to the task, it will spit out oil thats say 230 degrees regardless if the oil comes in at 280 or 260 degrees. This really comes into the equation when pressures and surface temps get high, as in racing.

Friction is a trade off when you think about it. Friction equals heat dissipation (or making heat if you want to put it that way). The longer the oil touches a surface, the longer it has time to transfer heat. Friction is also part of an oil having a higher load capacity. Obviously too much is a bad thing but when we are talking about going from a 0w-20 to a 5w-30, its not a huge difference. Going to a 20w-50 is a completely different story which is where different bearing clearances come in to play. Guess what? 0w-20 has less friction than thicker oils but it also has less of a load bearing capacity. Pick one side. I actually race my car so I chose the less efficient side.

Thats not how it works, not even slightly. You have a gross misunderstanding of how thermodynamics works. If everything else remains the same an increase in temperatures means you have reduced the cooling efficiency not increased it. These systems all reach equilibrium, if they reach that at a higher temp it’s less efficient at removing heat. If what you are saying was true then we would not need thermostats or speed controlled pumps for when it was cold.

On top of that the difference between 30 and 50 weight at race temps is like 1-4 cp. This is because at higher temps the oil is relying on its base stock rather then the additives.

The reason you pick an oil is due to tolerances at cold start and before heavy loads where temps build. Race engines typically have larger tolerances to handle higher pressure and use an oil to match it. But go look at f1 and they are using less then 0w, there is more to it and bearing design and tolerance has a massive impact. You will do some amount of damage to a modern oem engine by running such thick oil every time you start it, but you do what you want.

 

[Evolution]

Thats not how it works, not even slightly. You have a gross misunderstanding of how thermodynamics works.

On top of that the difference between 30 and 50 weight at race temps is like 1-4 cp. This is because at higher temps the oil is relying on its base stock rather then the additives.

The reason you pick an oil is due to tolerances and cold start and before heavy loads where temps build. Race engines typically have larger tolerances to handle higher pressure and use an oil to match it. But go look at f1 and they are using less then 0w, there is more to it and bearing design and tolerance has a massive impact. You will do some amount of damage to a modern oem engine by running such thick oil every time you start it, but you do what you want.

If that isn't how it works then how is that real life results that i have seen many times? I don't care about what F1 does, we have normal passenger cars, not multi-million dollar race cars built for every aspect of hp possible. They don't care about longevity as long as it makes power and last 1 race. They run something like a 0w-70 anyways and dont think its anything close to normal oil.

I think you are getting confused on what I am saying. I have not once said run a crazy thick oil in our Supras. No, not even close. I have said oil weight has to do with clearances. Same as you. All I have been saying is A - a thicker oil is better since it typically has a better load capacity (this is in general and not specifically related to a supra) and B - thicker oil runs hotter. How and why is we can disagree on.

One thing I do know is that I have more actual hands on experience about this exact subject then you with real world testing. No here is a link or a chart, I'm right! Specing out engine builds is what I do everyday and I have enough Baja 1000, formula d, Rolex series and 6 second drag car builds to back it up.

 

[3TMagnetMan]

So is everyone saying running 0w40 5w40 is ok to use on our cars

 

[JOutterbridge]

So is everyone saying running 0w40 5w40 is ok to use on our cars

I'd recommend using what's good for your engine based on climate. As long as it matches your driving style and intended use of course

0 and 5W 40 are pretty good at sub freezing temps...

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