Is my oil temp too low?

[malibuguy79]

Just installed an oil temp gauge in my autocross car. Its in the bottom of the sump.

Took it for a ride last night to see where it wants to be and it stays between 150-160⁰. Even when I let it sit and hot idle for 15min at a friends house it only got to 160⁰. Came down to 150-152 nearly immediately when I started driving again.
Current oil is HPL pcmo 5w30. The car runs a front splitter that goes to the axle line however the fan for the a2w intercooler does run all the time and is immediately in front of the motor. Cooling system hangs out around 190⁰. Oil pan is modified with trap doors and has about ½ quart added capacity over stock.

I guess ultimately I really cannot do much about it. Next event is in a couple weeks but I cannot imagine oil temps getting much hotter.

A customer of mine with a 4efte Starlet runs around the same temps...maybe 5-10⁰ more at most. Same sensor location and same brand gauge.

 

[TurboZedd-R]

Type of car, power, oil cooler? What are oil temps while racing would be the more important question.

 

[oil pan 4]

Base your oil viscosity on max temperature.
If you only ever see 150 to 160f you may be a really good candidate for an oil that ends in 20.
It seems almost like you need a coolant to oil heat exchanger. 190f would be a better temperature all around.

 

[nascarnation]

I assume with autocross your total "lap" time is short and you really don't build up heat like you would in a road course circuit in a 20 lap race. If your vehicle can use the added power, thin oil should give you better times. But of course in autocross handling (and driver skill) is paramount. When I used to crew for an SCCA racer, he'd come up with some small improvement that was difficult to implement and I'd tell him "why don't we leave the car alone and you just screw up one less corner during the race".

 

[malibuguy79]

Base your oil viscosity on max temperature.
If you only ever see 150 to 160f you may be a really good candidate for an oil that ends in 20.
It seems almost like you need a coolant to oil heat exchanger. 190f would be a better temperature all around.

Just going to rock it as is with the gallons of 5w30 I already paid for but this tells me the previous 5w40 I was using was definitely not in its happy spot

 

[nicholas]

Those are quite cool temps.....
What is the ambient temps you are seeing

 

[kschachn]

Just going to rock it as is with the gallons of 5w30 I already paid for but this tells me the previous 5w40 I was using was definitely not in its happy spot

Why not? What makes it unhappy? Especially if you’re worried the operating temperature is too low.

 

[vavavroom]

You could check sensor accuracy. This would have been easy to do before installing the sensor. Is there a calibration option?

 

[oil pan 4]

Why not? What makes it unhappy? Especially if you’re worried the operating temperature is too low.

Oil that's too cool increases wear. Also when too cool oil picks up water. The water pulls acid from carbon dioxide, sulphur and nitrogen dioxide. That in turn eats up the oils TBN and oxidization value. Acids plus water gives corrosion, inside the engine.

 

[kschachn]

Oil that's too cool increases wear. Also when too cool oil picks up water. The water pulls acid from carbon dioxide, sulphur and nitrogen dioxide. That in turn eats up the oils TBN and oxidization value. Acids plus water gives corrosion, inside the engine.

So a thicker oil will run warmer and help.

 

[oil pan 4]

So a thicker oil will run warmer and help.

Not enough to make a difference.
Then the thicker oil will be further outside of the 10 to 12cst ideal viscosity range and be more likely to hold air, foam foam up and again holding on to air, water and combustion byproducts making acids, rust, ect.

 

[kschachn]

Not enough to make a difference.
Then the thicker oil will be further outside of the 10 to 12cst ideal viscosity range and be more likely to hold air, foam foam up and again holding on to air, water and combustion byproducts making acids, rust, ect.

How is it ideal? And it will help to warm up, shear heating in oil is the largest contributor to temperature.

And as for the rest of what it will do, how is that related to grade?

Perhaps only for that 15W-45 oil you were using.

 

[oil pan 4]

How is it ideal? And it will help to warm up, shear heating in oil is the largest contributor to temperature.

And as for the rest of what it will do, that’s silly. It won’t do any of that.

Then thicker oil it is.

 

[kschachn]

Then thicker oil it is.

At least you’d have a higher MOFT for this autocross application. That seems as though it’s a good idea to me.

 

[AEHaas]

My 812 Superfast Ferrari specs a 40 grade oil but I use a 30 grade oil. It never gets above 180F. It runs at 170-175 in town and maybe 165F on I-75 doing 75 MPH plus...
The coolant is always around 180F regardless of the oil temperature. It gets up to temperature in 2 - 3 minutes of driving whereas the oil take around 15 minutes to get to 170F. Most local driving is less than 20 minutes so I run cool.
Quality oil analysis shows minimal water, 2 - 3% fuel dilution and HTHS values around 3.2 for the used oil. Wear is about zero.
Ali

 

[OilUzer]

My 812 Superfast Ferrari specs a 40 grade oil but I use a 30 grade oil. It never gets above 180F. It runs at 170-175 in town and maybe 165F on I-75 doing 75 MPH plus...
The coolant is always around 180F regardless of the oil temperature. It gets up to temperature in 2 - 3 minutes of driving whereas the oil take around 15 minutes to get to 170F. Most local driving is less than 20 minutes so I run cool.
Quality oil analysis shows minimal water, 2 - 3% fuel dilution and HTHS values around 3.2 for the used oil. Wear is about zero.
Ali

Weren't you using xW20 for a while due to your driving conditions and needs? i.e. limited to city driving or speed limits on our freeways.

Any major difference between the two as far as the data you were collecting and UOA, etc.

 

[Jetronic]

How close are you to the bottom or material of the sump? could you be reading the temperature of that?

These temperatures wouldn't worry me at all, they are after all the coolest temps the oil sees, it will only get warmer anywhere else in the engine. And it would have been good to test the gauge and sensor accuracy in boiling water before install, Lord knows how far it's off....

 

[wpod]

Change the oil more often.