Does Motor Oil Self Correct for Viscosity

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AEHaas

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The engine oil sump temperature was around 225 F while driving around town in the Enzo using a 60 grade oil. It was only 180 F when using a 20 grade oil. Same engine load but for the internal effects of the oil itself.

Ali
 
Could you drive the Enzo on the track for 5 hours with a 20 grade? Maybe the 20 grade is only acceptable for around town.
Is it a good idea to drive around town with a 60 grade for the first 20 min? What about a 70 grade?
The "Thicker" oil heats up and thins out but it seems wrong to refer to that as self correcting.
Unless it's an SAE grade 0w-60, that would be closer to self correcting - for your Enzo.
 
A better test would be to cruise on the highway at the same speed/RPM for 15-20 minutes soon after the oil gets to near full operating temperature. Too many variables criusing around town in traffic.
 
Doesn't 180F with 20 grade sounds kind of low? like the engine hasn't fully warmed up yet?
Wonder what the water temps were with the 20 vs. 60?

I may buy a fast car when walmart starts selling Ravenol or the 60 grade in store.

Application Notes:
RAVENOL RHV Racing High Viscosity SAE 20W-60 is used as a special oil for long distance motor racing when vehicles are placed under extreme strain.

RAVENOL RSS SAE 10W-60 may be used as special oil for car racing series even under most difficult conditions.
 
Higher viscosity means more hydrodynamic friction which means more heat. It also increases the risk of aeration which can also mean more heat.

However, higher viscosity also increases the specific heat of the oil.

None of this should make a 45°F difference in sump temp.
 
Currently at an ambient temperature of 90 F the 812 Superfast runs a sump temperature around 175 F in town and 165 F on the highway at 80 MPH. It seems the water temperature is always around 10 F higher than the oil temp. This is with the Pakelo 5W40 in the sump.

Ali
 
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AEHaas said:
Currently at an ambient temperature of 90 F the 812 Superfast runs a sump temperature around 175 F in town and 165 F on the highway at 80 MPH. It seems the water temperature is always around 10 F higher than the oil temp. This is with the Pakelo 5W40 in the sump.

Ali
Click to expand...

What is your typical or average rpm in town vs. doing 80 mph on highway?
This car or racing cars must have a special cooling system. No?

I guess it depends on where the oil temp sensor is located but I've never seen 165F operating oil temperature with any average passenger cars or trucks that I've ever owned (i.e. the walmart cars).

Typically the oil temp is higher than water/coolant. your observation is the opposite. some cars with the oil to water heat exchanger try to keep the oil & water temps as close as possible. iirc, something to do with the fuel economy and expansion/contraction tracking each other ...

I see the typical oil temps anywhere from 5-30F higher than water once the engine has fully warmed up and typically over 190F ... 165F is on the cool side for the average passenger cars or trucks.

Does your car have a digital temperature display or a dial or analog gauge?
Sounds like this engine is designed for high(er) rpm or is happier when using the 60 grade or thicker oil in general ... or may be the 165F is the norm with this type of engine and it's just warming up for the race. I don't like high oil temps but also not used to very low oil temps either. I'm used to the typical 190-225F +/- range but I don't abuse my cars either.

How many gears does this car have? I guess you can always use a lower gear (and not lug the engine) when doing 80mph to increase the rpm and the oil temp if 165F is not desirable!
 
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I generally drive the car in Automatic transmission mode. It's a dual clutch 7 speed manual transmission with paddle shifting. Around town the gears vary. At 75-80 MPH it is in 7th gear at around 3,000 RPM. The oil pressure is in bypass at 80 PSI. An oil change is 12 qts.

The displays are digital.

ali
 
I was just curious about add-pack "activation" temperature since I've read about it on bitog ... and found a bitog discussion and some of the I assume experts were basically saying to get the engine oil to 80C (176F). However, it make sense that internal parts are running much hotter than the oil temp reading of in this case 165F ... Also have to consider the sensor location and accuracy.


from bitog:

"with ZDDP to work the oil temps must get up to at least 80C for the plating effect to occur."

"These additives work better at temps but the localized temp. in the contact zone will get WAY above 80C, and will be activated by that heat. Pressure (from contact) also increases the hardness/thickness of the zinc tribo films."
 
AEHaas said:
Currently at an ambient temperature of 90 F the 812 Superfast runs a sump temperature around 175 F in town and 165 F on the highway at 80 MPH. It seems the water temperature is always around 10 F higher than the oil temp. This is with the Pakelo 5W40 in the sump.

Ali
Click to expand...

Noticed you are using Pakelo ... I had never heard of it but I also don't own any fancy cars.

What kind of cert, approval or spec is listed or required for your engine oil?

How does Pakelo compare to Ravenol and can you use a fancy German oil in a fancy Italian car or is it forbidden? lol
 
I wouldn't think so, not completely, or else there would be no noticable fuel economy benefit to using lower viscosity oils. Right?
 
AEHaas said:
The engine oil sump temperature was around 225 F while driving around town in the Enzo using a 60 grade oil. It was only 180 F when using a 20 grade oil. Same engine load but for the internal effects of the oil itself.

Ali
Click to expand...
What Artificial Intelligence is incorporated in engine oils that would provide a feedback mechanism to correct for viscosity changes?
 
"Typically the oil temp is higher than water/coolant. your observation is the opposite."

Yes. On the way to work this morning, about 20 minutes driving:

IMG_1599.webp
 
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