17+ engine oil temps

[ZDan]

Originally Posted by norcalpb

It’s not a degradation of the oil, it’s the reduction in oil pressure that is a problem.

Ah, but we have data showing that the pressure drop from running a cooler exactly negates the pressure benefit from having cooler oil!

Check it:
https://www.ft86club.com/forums/showthread.php?t=91820


Temps are 20-25F cooler with the oil cooler, but the pressure is actually the same, ~7.5psi/1000-rpm for 5W30 oil, at ~250F with cooler or at ~272F without the cooler.

[StraightOuttaCanadaEh]

What are you two saying, in plain english

[new2subaru]

Originally Posted by StraightOuttaCanadaEh

What are you two saying, in plain english

Oil pressure may get the oil to where it's supposed to be but if the viscosity decreases the lubrication properties follow.

It's not good.

Mine runs around 230F with a cooler. I'm NA. I was leaving the track at 250+ last year after 5-6 laps.

[ZDan]

Originally Posted by new2subaru

Oil pressure may get the oil to where it's supposed to be but if the viscosity decreases the lubrication properties follow.
It's not good.

Quantify how "not good".
Hydrodynamic wedge is a thing. Oil temps do get higher with sustained high rpm, but at the same time rpms provide film strength. 270F is not a problem for lubrication properties of good synthetic oil. Might as well throw this in again, here's how Ford characterized oil temps in the Mustang's factory service manual:
38-60° C (100-140° F) (low)
61-137° C (142-279° F) (normal)
138-146° C (279-295° F) (warm)
147-160° C (297-320° F) (hot)

[new2subaru]

Dan, can't quote you for some reason.


You graph shows a cooler oil works better than a hotter oil...


I've seen you post the Ford temps before. I'm not sure what they prove TBH.

Why would you want your oil at 270F if a lower temp is possible? It works better at lower temps...The ideal temp for engine oil is 100C or 220F. Let's not forget besides lubrication that oil carry's away heat from engine components. What are your coolant temps at 270F oil temp?

I will never be convinced that 270-290F is okay on track. The ideal operating temp is 220F. Many start to break down at 270ish. This also depends highly on the type of oil but maybe a simple cooler is saving me $100/oil change of racing oil...

Here is what I use

https://www.mobil.com/english-ca/pas...obil-1-fs-0w40

The HTHS is fairly good with this oil. I'm sure there are better but every penny counts.


I've switched back to an OW 20 now that it's cooler. Why? Because it will perform better than OW 40 and am no longer tracking.


Anyways, those are my thoughts and I'm not going to debate it any further. This can be argued from here until Sunday...

[ZDan]

Originally Posted by new2subaru

You graph shows a cooler oil works better than a hotter oil...

How does it show that? Define "works better". Data shows that oil pressure is the same with or without oil cooler.

I've seen you post the Ford temps before. I'm not sure what they prove TBH.

Doesn't "prove" anything, it just demonstrates that the temperatures considered "hot" by people with vast volumes of test data are way above 270F...
I believe C7 Corvettes exceed 300F before "limp mode" is induced.

Why would you want your oil at 270F if a lower temp is possible? It works better at lower temps...The ideal temp for engine oil is 100C or 220F.

That is a standard *reference* temp, it's not "ideal".
I looked into it and determined that for my usage, 270F for limited time at the track didn't appear to be a problem given good 30wt synthetic oil and reasonably frequent changes.
If I were endurance racing it I'd probably run a cooler.

Let's not forget besides lubrication that oil carry's away heat from engine components. What are your coolant temps at 270F oil temp?

Coolant temp stays in the middle of the range, never indicates running hotter than normal.

I will never be convinced that 270-290F is okay on track. The ideal operating temp is 220F. Many start to break down at 270ish. This also depends highly on the type of oil but maybe a simple cooler is saving me $100/oil change of racing oil...

270F is not 290F. But even 290F *may* be OK for limited usage... For sure at 290F I'd more strongly consider running a cooler. At just over 270F I don't think it's necessary for my usage.
100C (212F) is a standard reference temp for oil, it's not necessarily "ideal".
Plenty of "standard" off-the-shelf synth oils are good to well over 300F
I can't find it at the moment, but there is a thread where a guy reported his oil analysis lab results post tracking at 270+F without a cooler, no problems. No indications of oil breakdown or indication excessive wear indicated.

For those who are very concerned about tracking without a cooler, I'd recommend getting analysis done and learn for yourself what is happening to the oil itself and whether engine metals are being deposited into it with hard usage.

Here is what I use
https://www.mobil.com/english-ca/pas...obil-1-fs-0w40

I've heard good things about Mobil1 0w40.
I run Total 5w30 synthetic (what the trusted local shop uses) for street/track season and switch back to 0w20 after track season.

Anyways, those are my thoughts and I'm not going to debate it any further. This can be argued from here until Sunday...

I looked into it thinking I'd confirm the "you need to run an oil cooler" dictate. But I haven't found any evidence that I do.
Meanwhile, I *did* find multiple instances of oil leaks associated with add-on oil coolers, including a loss-of-engine at the track (which honestly could have been a lot worse for others as well with oil on the track!) and more than one oii fire, one leading to total immolation of the car!

For casual 15-20 minute at time HPDE usage, with frequent changes and 5w30 synthetic, I don't think an oil cooler is necessary, or even a good idea. I don't think it solves any serious problem, and adding an oil cooler is not a zero-risk proposition...

[NoHaveMSG]

Originally Posted by new2subaru

Dan, can't quote you for some reason.


You graph shows a cooler oil works better than a hotter oil...


I've seen you post the Ford temps before. I'm not sure what they prove TBH.

Why would you want your oil at 270F if a lower temp is possible? It works better at lower temps...The ideal temp for engine oil is 100C or 220F. Let's not forget besides lubrication that oil carry's away heat from engine components. What are your coolant temps at 270F oil temp?

I will never be convinced that 270-290F is okay on track. The ideal operating temp is 220F. Many start to break down at 270ish. This also depends highly on the type of oil but maybe a simple cooler is saving me $100/oil change of racing oil...

Here is what I use

https://www.mobil.com/english-ca/pas...obil-1-fs-0w40

The HTHS is fairly good with this oil. I'm sure there are better but every penny counts.


I've switched back to an OW 20 now that it's cooler. Why? Because it will perform better than OW 40 and am no longer tracking.


Anyways, those are my thoughts and I'm not going to debate it any further. This can be argued from here until Sunday...

You need to do a bit of research. There is so much documented info here from people shearing their UOA's which would be the ultimate deciding factor. There was someone in the UOA thread that regularly tracked a turbo car on E85 and sent their oil sample into blackstone labs at 7500 miles. They said that mileage was fine.

High quality synthetics can handle 270F without any trouble. 300V has been tested to ASTM D4741 with no signs of sheer loss or deterioration. That testing is something like 40 hours at 150C. Wish I still had the link.

I regularly see 270F on track and I have my oil changes at 7500. All my UOA's have come back clean. Getting ready to do another UOA. I can post that one if you want evidence but there is already plenty of that in the UOA thread.

[ZDan]

Originally Posted by StraightOuttaCanadaEh

What are you two saying, in plain english

What I'm saying: you probably don't need an oil cooler for track usage. Run good 0w30 or 5w30 (or 0w40 or 5w40) synthetic and change at reasonable intervals.

[TunaNoCrust]

It really comes down to taking your operating temperature range, matching the viscosity of the oil at that temperature range to your clearances and material. Hence the oil viscosity temp charts in car manuals.

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[Blue-Sensei]

I've stuck with 0w20. I'm boosted, but it's also my DD. I don't think I've seen my oil temps creep past 240F even with 100F+ ambient temps. Typically temps are around 210-220F when ambient temps are 75-90F and 180-210F for lower temps. I'm in VA where year round temps are ~-10F to ~105F
Forgot to add that I do have an oil cooler.

[new2subaru]

You can show me all the UOA's and maximum oil temp stats you like.

I will never be convinced that going to track with oil that has seen 7500k is better than a fresh oil change or operating at 270 is better than operating at 230. I know what is written and have done research.

Bottom line, I have been looking after a fleet of trucks and equipment for the last 25+ years. All of the oils, air filters and tires are changes WAY before manufacturers recommendations and I've never even seen as much as a flat tire, never mind premature engine or transmission wear. These methods have served me well.

Just because you can do these things doesn't mean is the best thing to do. I drop my oil every 3rd track day. If I get it on sale it costs me $10/event. It's extremely cheap compared to other consumables...


Just my preference

[NoHaveMSG]

Originally Posted by new2subaru

You can show me all the UOA's and maximum oil temp stats you like.

I will never be convinced that going to track with oil that has seen 7500k is better than a fresh oil change or operating at 270 is better than operating at 230. I know what is written and have done research.

Bottom line, I have been looking after a fleet of trucks and equipment for the last 25+ years. All of the oils, air filters and tires are changes WAY before manufacturers recommendations and I've never even seen as much as a flat tire, never mind premature engine or transmission wear. These methods have served me well.

Just because you can do these things doesn't mean is the best thing to do. I drop my oil every 3rd track day. If I get it on sale it costs me $10/event. It's extremely cheap compared to other consumables...


Just my preference

I am not talking about tracking after 7500K. We are talking about intervals of 7500k. If oil pressures are stable and adequate at 270F then what is wrong with that temperature? Data shows quality oils can handle it.

My pops did fleet maintenance for Winco Foods and they would always UOA their trucks and extend oil changes out to the max, often times beyond factory recommended intervals. That worked well for them too so

[new2subaru]

Originally Posted by NoHaveMSG

I am not talking about tracking after 7500K. We are talking about intervals of 7500k. If oil pressures are stable and adequate at 270F then what is wrong with that temperature? Data shows quality oils can handle it.

My pops did fleet maintenance for Winco Foods and they would always UOA their trucks and extend oil changes out to the max, often times beyond factory recommended intervals. That worked well for them too so

There you go, to each his own

[TunaNoCrust]

Maintenance on a truck and performance on a race car are very different things.

Doing something because it works for you and doing something because research, data, and results indicate you should are very different...you may end up with the same action, but only one of them will tell you how you arrived there.