Oil Cooling - An In-Depth Look

[Adam_L]

The first number ( 0w, 5w) is how thick or thin the viscosity is. 0w is best for the lowest start up wear, as it's the thinest ( not as thick of a viscosity), so it can get kicked up from the oil pan up into the camshaft/ pistons faster ( less start up wear is key**).

The second number ( 20, 30 , etc), is how fast you oil reaches operating temperature. So a 20 will reach operating temps faster then 30. So a 20 is good for winter time....colder temperatures outside.

I also heard, that 0w-20, and 5w-20 are only synthetic oil ( possibly 0w-30 as well). Not sure why, it might be the oil base stock used, and going as thin of a viscosity. ..the only way to achieve that is with synthetics.

[Tristor]

There's a disturbing amount of misinformation in this thread... I'm not even really sure where it's coming from as I thought oil grades were pretty self-explanatory.

Oil grades are set by the SAE and are correlated to viscosity, but are not themselves a viscosity rating. The first number in a multigrade oil (before the W) is the SAE oil grade when the oil is cold. The second number in a multigrade oil is the SAE oil grade when the oil is at operating temperature. Whether an oil is a particular grade or not does not affect whether it is made from synthetic base stocks.


0w40 vs 5w30, yes there are engineering tradeoffs made in viscosity in order to make multigrade oils possible. This is physics, not magic. So in order to achieve a higher SAE grade (based on viscosity) at temperature, the viscosity when cold is also going to be affected. The difference between 0w40 and 5w30 cold viscosity on Mobil 1 is negligible and is more than made up for in the benefits to oil pressure when up to temp /if/ you need that benefit.


Subaru and Toyota both specify oil by geographic region and climate. If you don't live an area which snows regularly you can very easily run 5w30 year-round, you do not need to switch oil grade during the winter.


https://www.lubricants.total.com/what-are-oil-grades

[Bonburner]

haha my bad, i had them jumbled up in my head ~

but yeah, check the actual specifications for the viscosity because different manufacturers have different viscosities for same oil weights.

[Adam_L]

Originally Posted by Tristor

There's a disturbing amount of misinformation in this thread... I'm not even really sure where it's coming from as I thought oil grades were pretty self-explanatory.

Subaru and Toyota both specify oil by geographic region and climate. If you don't live an area which snows regularly you can very easily run 5w30 year-round, you do not need to switch oil grade during the winter.


https://www.lubricants.total.com/what-are-oil-grades

I hope you're not talking about me. My local Toyota dealer gives 0w-20 year round, if you own a FRS (bring it in for a oil change) , yet temperature there year round is 40 F (coldest) to 80 F (hottest).

You don't want to mix grades of oil in a engine ( ex. 1q of 5w-30 + 3q of 0w-20 , etc). However it is OK to have a Spring/summer oil of say 5w-30 , then for Fall /Winter go to a 0w-20 or 5w-20. Is this mis-information? I haven't heard of a engine failing given this, (however I suppose each manufacture has their own reasons for prescribing a certain grade of oil , per car / engine).

[VerusEric]

Originally Posted by Adam_L

The second number ( 20, 30 , etc), is how fast you oil reaches operating temperature. So a 20 will reach operating temps faster then 30. So a 20 is good for winter time....colder temperatures outside.
.

The second number is the *viscosity* when the oil is hot; not how quickly it reaches operating temperature.

It is a common misconception that oil weights need to be changed in the winter/summer. With water cooled engines (which the FA20 is water cooled), the oil temperature is the same regardless if it is -20 or 120 out. As long as the cooling system is able to maintain the temperature set by the thermostat, the oil temperature should be exactly the same regardless of ambient air temp.

In air-cooled engines, the oil does need to be changed for the season; as oil temperature ranges quite significantly depending on the ambient air (which is how the engine is cooled).

Thanks,
Eric

[steve99]

Originally Posted by VerusEric

The second number is the *viscosity* when the oil is hot; not how quickly it reaches operating temperature.

It is a common misconception that oil weights need to be changed in the winter/summer. With water cooled engines (which the FA20 is water cooled), the oil temperature is the same regardless if it is -20 or 120 out. As long as the cooling system is able to maintain the temperature set by the thermostat, the oil temperature should be exactly the same regardless of ambient air temp.

In air-cooled engines, the oil does need to be changed for the season; as oil temperature ranges quite significantly depending on the ambient air (which is how the engine is cooled).

Thanks,
Eric

the FA20 oil temps climb rapidly with sustained hard driving not unusual to see 250F plus if no oil cooler fitted , these type of temps will see oil viscosity less than what its rated ( rated at 212F- 100C) . Coolant temps stay arround the 190F.


agree in normal road driving the oil temps are pretty stable in 190-200 area, but as soon as you track or auto cross oil temps rise significantly.



hence unless you have a suitable oil cooler to keep temps arround 212F max most people are better running a 5w30 or 0w30 if they do a bit of hard driving or track without oil cooler in preference to the 0w20.

[VerusEric]

Originally Posted by Adam_L

The first number ( 0w, 5w) is how thick or thin the viscosity is. 0w is best for the lowest start up wear, as it's the thinest ( not as thick of a viscosity), so it can get kicked up from the oil pan up into the camshaft/ pistons faster ( less start up wear is key**).

The second number ( 20, 30 , etc), is how fast you oil reaches operating temperature. So a 20 will reach operating temps faster then 30. So a 20 is good for winter time....colder temperatures outside.

I also heard, that 0w-20, and 5w-20 are only synthetic oil ( possibly 0w-30 as well). Not sure why, it might be the oil base stock used, and going as thin of a viscosity. ..the only way to achieve that is with synthetics.

Originally Posted by steve99

the FA20 oil temps climb rapidly with sustained hard driving not unusual to see 250F plus if no oil cooler fitted , these type of temps will see oil viscosity less than what its rated ( rated at 212F- 100C) . Coolant temps stay arround the 190F.


agree in normal road driving the oil temps are pretty stable in 190-200 area, but as soon as you track or auto cross oil temps rise significantly.



hence unless you have a suitable oil cooler to keep temps arround 212F max most people are better running a 5w30 or 0w30 if they do a bit of hard driving or track without oil cooler in preference to the 0w20.

I agree. As you begin seeing higher temps, you'll have to run either an oil cooler or thicker oil or possibly both.

You should still be able to run the car with the same oil in the winter and summer though; unless the oil cooler is an air to oil cooler and oil temps are indeed significantly cooler in the winter months.

Thanks,
Eric

[JIM THEO]

What about fitting a NED (https://www.nedautoparts.com/collect...oem-subaru-brz) factory style water to oil cooler for hard street use regardless of oil viscosity, it will heat faster the oil while could keep it's temp normal?
But it is fed water from throttle body not from water cooler as Cusco similar kit does so may be it is less effective.
My concern also is if it increases remarkably water temps so the final result is worse than without oil cooler...any experiences?

[steve99]

Originally Posted by JIM THEO

What about fitting a NED (https://www.nedautoparts.com/collect...oem-subaru-brz) factory style water to oil cooler for hard street use regardless of oil viscosity, it will heat faster the oil while could keep it's temp normal?
But it is fed water from throttle body not from water cooler as Cusco similar kit does so may be it is less effective.
My concern also is if it increases remarkably water temps so the final result is worse than without oil cooler...any experiences?

The radiators on these cars have a lot of spare capacity, i have one of the forrester coolers installed, no noticable increase in coolant temps. It takes about 10-15 degrees of oil temps , but after sustained track use oil temps will still climb as it runs out of heat transfer capacity. The coolant temps stay normal though.


Its a good option for street and mild track use.


If your hard track user get a full oil cooler


Bunch of info here


http://www.ft86club.com/forums/showthread.php?t=93127

[Ultramaroon]

What's the best oil cooler for shitty valve springs?

[atomicalex]

Thanks everyone for this good thread. The Forrester solution looks good for me for now until I am ready to take a bigger leap. It will give me a little bit of extra cooling for the light track work I get in and faster warmups for winter fun.

[86TOYO2k17]

I have a oil cooler with the mocal thermostat plate. Anyone know where i can get a higher thermostat to swap in? Pref 195-205F or 90-95C.

[Semiihcircle]

My oil gets really hot when on the highway cruising above 3500 rpm

Sent from my SM-G973U1 using Tapatalk

[86MLR]

Some interesting reading

https://www.pegasusautoracing.com/do...ocID=TECH00133

http://www.mocal.co.uk/ocfaq.html

I personally use a Forester heat exchanger, more for warming up the oil, it doesn't really do alot for cooling.

If I needed more cooling I would get a larger laminova.

The benifits far outweigh the small additional cost.