Oil viscosity relationship to oil temps

[Karl]

I was told a while ago at a track day that a high velocity oil say 10-50 would reduce oil temps. I was running 5-30 and would reach 150 + after a few laps.

After researching this myself i have found that thicker oil will actually increase oil temp as it adds more friction and struggles to disperse the heat as much.

Im after someone to clarify as im undersidered if i should run a thicker oil or not. As the car doesnt consume any at 5/30.

Cheers

[eskimo_firefighter]

150C oil temperatures? That's extremely high from what I've researched people advise to not go over 130ish.

From my basic understanding I thought running a higher viscosity is to lower oil temps when the motor is hot, how ever going too high may be detrimental to your motor on cold starts as it struggles to move around the motor as it's too thick.

I would also like to know more in regards to this too. As I run a 5w40 in my AP1 and I literally do not burn a drop after full track day, however I have no clue what my oil temperatures are like as I do not have gauges installed.

[Karl]

150C oil temperatures? That's extremely high from what I've researched people advise to not go over 130ish.

From my basic understanding I thought running a higher viscosity is to lower oil temps when the motor is hot, how ever going too high may be detrimental to your motor on cold starts as it struggles to move around the motor as it's too thick.

I would also like to know more in regards to this too. As I run a 5w40 in my AP1 and I literally do not burn a drop after full track day, however I have no clue what my oil temperatures are like as I do not have gauges installed.

Thats what i was told, But i researched it and i found the opposite answer.
Also just driving down the M2 on a 33 degree day my oil temps were 117 degrees, coolent at 87.

[tinkerbell]

where is the temperature sensor located? in the sump?

what size oil cooler do you have?

instead of worrying about subtle things like your oil viscosity - i suggest you worry about why your engine oil is getting so hot in the first place!!!

[tinkerbell]

fwiw - i used to run 10W-60 when i was competing in the supersprint championships...

[eskimo_firefighter]

where is the temperature sensor located? in the sump?

what size oil cooler do you have?

instead of worrying about subtle things like your oil viscosity - i suggest you worry about why your engine oil is getting so hot in the first place!!!

I agree, but the fact that your temps are that high and you don't burn any oil or have any engine problems is a good sign.

Maybe there's an issue with the sensors as definitely at those temperatures it would burn heaps of oil would it not? First I've heard of oil temperatures that high.

[Karl]

where is the temperature sensor located? in the sump?

what size oil cooler do you have?

instead of worrying about subtle things like your oil viscosity - i suggest you worry about why your engine oil is getting so hot in the first place!!!

Oil filter sandwhich plate
Nun install just the stock Type R one
Travelling about 110 down M2 on a hot day, Sitting just bellow 4000 rpm. Thought the oil temp would have been normal.

Oil pressure at idle is 19 psi at full temp. Peaks around 76 psi?

[tinkerbell]

the only way to bring oil temp down effectly is via an air-liquid cooler.

changing viscosity will not bring temps down from where you have them now...

oil temps should be below coolant temperature in normal driving.

on track you need the oil temp below 120 always.

[Fallenangel]

I had temps of 120 deg crusing @ 110km/h on a cold winter night. Motor was worn since it had 300,000kms. First simple thing i'd check would be your thermostat and see if thats working, since our water temps are used to cool oil temps via thermal transfer. There might be other issues inside the engine. Very weird that its not burning any oil since its running so hot. As mentioned above, get a oil cooler and see if that helps.

Also if you could provide a bit more info on the car that'll be good. Mods/kms etc.

Your Oil Pressure seems normal, so the oil pump should be alright. Although your temp is way high.

[Karl]

kms 161000
Mods I-H-E, tune
Koyo alloy radiator
Mugen thermostat


Car feels and drives fine. Oil is replaced every 1 year. Gets around 4000km in that time.
Oil looks new when drop it.


Normal driving it sits around 90. Thats stop start around 60-80km/h.
Only get high temps on constant speed down a free way.

[mugsee]

@Karl, What oils are you comparing?

on track you need the oil temp below 120 always.

Why?

[Karl]

@Karl, What oils are you comparing?



Why?

Not comparing any oils. Last time i was at the track i got told to increase velocity to decrease oil temps.
And ive done some research on the topic and ive found that to be incorrect " correct me if im wrong". That thicker oil increase temp as its increases friction.

Has any one with stock setup actually seen there temps. I thought 115 odd was normal on freeway driving on hot days. Due to constant high rpm

[tinkerbell]

Why?

why aim to keep temps below 120?

because >120 means your oil cooling system is probably inadequate...

edit - ideally in a circut racing car - you should be aiming for around or below 100 degrees...

[Apu]

I agree with Tinkerbell.

I find it really strange that you are getting high temps during highway runs...unless you are constantly redlining.

My turbo MX5 gets up to about 110degC on the track and only hits that temp when stuck in traffic. As soon as I get moving, the oil temp drops. Anything above 120degC and oil starts breaking down, and that's when you start getting long term problems.

You might have other problems with your engine.

[mugsee]

because >120 means your oil cooling system is probably inadequate...

If having a cooling system that doesn't keep oil temps below 120degrees on paper is what we need to worry about, I'm fine having an inadequate cooling system. A good quality oil will handle 120degrees+ without shearing or breaking down, so temperature is not a problem for lubrication purposes. Of course, a good quality oil should also provide enough lubrication to reduce friction and lower temps, even if only by a little bit.

If on the other hand power is adversely affected by the change in heat, then I'm on board for reducing oil temperatures.

130degrees is normal (hot) for a DC2R, but obviously not desirable. https://www.youtube.com/watch?v=s4dF4cFHl6Y

Oh, and 115degrees is definitely on the hot side for freeway driving @ 4000rpm. Has it always done this?