Engine oil viscosity
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7th Gear
Joined: Jul 2013
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Engine oil viscosity
When my car is on the track my engine temp gets up to 250deg. I live in south Florida where the temp really gets lower than 55degs most of the time track temp is over 80. I always run a full synthetic oil. I drive my car to the track. Any suggestions on which viscosity should I use.
Team Owner
Joined: Sep 2000
Posts: 25,029
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From: Far NW 'burbs of Chicago
St. Jude Donor '13
We have a retired oil engineer who posts here occasionally, he says the desired oil temp to go full throttle, with generic 5W-30 in a generic engine, is 190-250 or perhaps 180-260. Mobil1 in a Corvette engine might have somewhat different numbers, but GM won't talk.
Based on that, your 250 isn't a problem. If you want an oil that's good for the street but gives a bit more protection at high temps, you might try 0W-40.
If you have the stick shift GS and dry sump engine, you have an oil cooler already, if you don't have one then it would be a reasonable addition. The smaller Z51 unit would probably be a nice compromise, the big ones tend to overcool the oil for street use.
Based on that, your 250 isn't a problem. If you want an oil that's good for the street but gives a bit more protection at high temps, you might try 0W-40.
If you have the stick shift GS and dry sump engine, you have an oil cooler already, if you don't have one then it would be a reasonable addition. The smaller Z51 unit would probably be a nice compromise, the big ones tend to overcool the oil for street use.
Racer
Joined: Jul 2011
Posts: 370
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From: Wellington FL
250 degF is fine
If you are driving a C6, then 250 degF oil temp is totally fine and may indicate that you are not yet pushing the car real hard.
I have an 09 C6 Z51 and have seen about 275 degF at the end of about 25 minutes of track driving (Homestead). At that temp, I just back off the car and let it cool a bit to end the session. Last time out I ran 0W-40 Mobil 1 just to increase high temp viscosity.
I have heard that a warning light come on at 302 degF, but did not want to test it. Many who drive track frequently see 275+ and find that oil temp is a limiter. At 250, you are still in a very safe range.
I have an 09 C6 Z51 and have seen about 275 degF at the end of about 25 minutes of track driving (Homestead). At that temp, I just back off the car and let it cool a bit to end the session. Last time out I ran 0W-40 Mobil 1 just to increase high temp viscosity.
I have heard that a warning light come on at 302 degF, but did not want to test it. Many who drive track frequently see 275+ and find that oil temp is a limiter. At 250, you are still in a very safe range.
Team Owner
Joined: Sep 2000
Posts: 25,029
Likes: 2,719
From: Far NW 'burbs of Chicago
St. Jude Donor '13
If you are driving a C6, then 250 degF oil temp is totally fine and may indicate that you are not yet pushing the car real hard.
I have an 09 C6 Z51 and have seen about 275 degF at the end of about 25 minutes of track driving (Homestead). At that temp, I just back off the car and let it cool a bit to end the session. Last time out I ran 0W-40 Mobil 1 just to increase high temp viscosity.
I have heard that a warning light come on at 302 degF, but did not want to test it. Many who drive track frequently see 275+ and find that oil temp is a limiter. At 250, you are still in a very safe range.
I have an 09 C6 Z51 and have seen about 275 degF at the end of about 25 minutes of track driving (Homestead). At that temp, I just back off the car and let it cool a bit to end the session. Last time out I ran 0W-40 Mobil 1 just to increase high temp viscosity.
I have heard that a warning light come on at 302 degF, but did not want to test it. Many who drive track frequently see 275+ and find that oil temp is a limiter. At 250, you are still in a very safe range.
IIRC, at 302' the cooling fan is commanded to high speed regardless of coolant temp, but you don't get a warning.
At 320', you get a DIC message something like "Hot Oil- Idle Engine".
Personally, I consider 190-250 to be the Normal range for 5W-30 oil temp, 250-302 to be "Caution", and 302 to be Redline. Just personal opinion, but I would run it exactly the way you are doing. Including 0W-40 for track.
