max oil temp ??
Thread Starter
Instructor
Joined: Jan 2006
Posts: 118
Likes: 0
From: el sobrante ca
max oil temp ??
My z51 oil temp gets up to 273 deg on 95 deg track days and some people have told me that the oil is only good up to about 250 deg.
Does anyone have any technical info that describes the max recommended operating oil temp for 5w-30 Mobil I ??
Does anyone have any technical info that describes the max recommended operating oil temp for 5w-30 Mobil I ??
Drifting
Joined: Feb 2007
Posts: 1,537
Likes: 1
From: Southlake Texas
Your oil should be fine at those temperatures.
Good synthetics like 5W30 Mobil 1 can easily handle 400F for short periods and can sustain 290F over prolonged use (I've used the Southwest Research Institute to test high temperature instrumentation and they have tested Mobil 1 at 400F).
EDIT: The 250F limit is usually for conventional oils.
Good synthetics like 5W30 Mobil 1 can easily handle 400F for short periods and can sustain 290F over prolonged use (I've used the Southwest Research Institute to test high temperature instrumentation and they have tested Mobil 1 at 400F).
EDIT: The 250F limit is usually for conventional oils.
Le Mans Master
Joined: Dec 2002
Posts: 7,588
Likes: 6
From: Montreal Qc
The problem is not the oil, Mobil 1 can take the heat, I'd say it's good for another 100 degrees. More to be concerned about is the plastic and rubber parts in your engine as the heat will make them brittle. On the bright side though I am told there is a high oil temp warning set by GM designers at 320 degrees, so you still haven't reached that point yet. 
I was in the same situation and ended up installing a Z51 rad and hooking up the OEM oil cooler lines to it, that has helped alot in bringing down my temps down 20 - 25 degrees. It will/can still creep up under hard tracking and hot days but still not as hot as before the swap.
I was in the same situation and ended up installing a Z51 rad and hooking up the OEM oil cooler lines to it, that has helped alot in bringing down my temps down 20 - 25 degrees. It will/can still creep up under hard tracking and hot days but still not as hot as before the swap.
Race Director
Joined: May 2001
Posts: 15,323
Likes: 2,077
From: Guelph, Ontario
One thing to remember is that even if your oil can handle the higher temps without breaking down, it'll still be considerably thinner! So if your oil temp is over about 250 degrees, that oil is very thin and is not protecting your engine very well at all. You have two choices if you're going to be consistently putting the oil under this much stress. One would be to switch to a thicker 10w40 oil, or second (and the more preferable choice of the two) would be to get a proper oil cooler that actually works as opposed to GM's pathetic attempt at one.
Drifting
Joined: Feb 2007
Posts: 1,537
Likes: 1
From: Southlake Texas
Miaugi makes a great point about high temperatures and plastics. Removing the plastic engine covers will also help cool the engine.
Also, Mobil 1 5W30 retains high film strength (and good viscosity) at elevated temperatures and will give you full engine protection at 290F and above.
Also, Mobil 1 5W30 retains high film strength (and good viscosity) at elevated temperatures and will give you full engine protection at 290F and above.
Last edited by WHT; Aug 13, 2007 at 07:31 AM.
Race Director
Joined: May 2001
Posts: 15,323
Likes: 2,077
From: Guelph, Ontario
To further elaborate on what I said before though, as oil gets hotter it gets thinner. So Mobil 1 5w30 at 273 degrees is actually thinner than a typical 5w20 oil would be at 200 degrees! So even if the oil doesn't physically break down, it is still far too thin to provide the necessary boundary lubrication in your engine. If you do nothing at all, and get high oil temps like that on a regular basis, your engine probably won't make it to 100k without needing a rebuild.
Team Owner
Joined: Sep 2003
Posts: 43,084
Likes: 33
From: Raleigh / Rolesville NC
M1 is good for well into the mid 300s. The LSx engines can take oil temp to 325 So in theory not a problem.
How ever, oil is part of your block cooling. Oil at 275-300 does not cool your block, this is why we say max of 250-260 for track days. If the oil temp gets above 260 to slow down and cool off.
For guys who do lots of track days, more then 3 a year, time to put an oil cooler in your car.
My oil use to run 250-260 consistently with an oil cooler. Now it is 240 consistently and my water temps are 200-205
How ever, oil is part of your block cooling. Oil at 275-300 does not cool your block, this is why we say max of 250-260 for track days. If the oil temp gets above 260 to slow down and cool off.
For guys who do lots of track days, more then 3 a year, time to put an oil cooler in your car.
My oil use to run 250-260 consistently with an oil cooler. Now it is 240 consistently and my water temps are 200-205
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Joined: Jan 2006
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I rebuilt the LT4 in my 944 conversion last year. Everyone was telling me how the normal operating temp for this engine was 230* coolant temp and 250* oil temp. Well, Bull S**t. The rod bearing were black and blue. And this was after using Castrol Syntech 20W50 exclusefully after breakin. The engine had 30k miles on it. The highest coolant temp I ever recorded was 260*. Since then I have improved the cooling system and added a BIG oil cooler. Now I have coolant temp around 190* on hot days. I wonder if it were not for the emissions standards, would GM be designing cooler running engines.?
