Ideal oil temp?

[NicTheMx5]

The internet gives broad temp ranges for oil, but just wondered if it varied between engine types?

Running castrol edge 5w40 in a forged turbo NA6 with a 13row oil cooler.
Oil thermostat is 85°c, and oil temp sits on 85°c and doesn't budge. Seems like the cooler works too well...

[NitroDann]

You need to ask your oil manufacturer.

[StillIC]

You need to ask your oil manufacturer.

Should each one of us individually ring up our current and all prospective oil manufacturers? Should every car enthusiast in the world with an oil temp gauge give all manufacturers a call? Is this the only way to obtain this information?

This seems like a good waste of human time and effort. Every other industry in the world publishes data sheets for its products. Individuals having to call a multi million/billion/trillion dollar manufacturer to find basic data about a product seems counter productive for humanity.

[greenMachine]

You need to ask your oil manufacturer.

Should each one of us individually ring up our current and all prospective oil manufacturers? Should every car enthusiast in the world with an oil temp gauge give all manufacturers a call? Is this the only way to obtain this information?

This seems like a good waste of human time and effort. Every other industry in the world publishes data sheets for its products. Individuals having to call a multi million/billion/trillion dollar manufacturer to find basic data about a product seems counter productive for humanity.

Cool down! (pun intended )

I'm with Dann on this one. Seems commonsense to do some research for yourself, and then if that isn't working, or your needs are sooo special, then ask your question with the relevant information to guide responses. PDS are a good start.

But then I'm an old fart. And I grew up when you couldn't believe everything you saw on the interwebz - not like now ...

[NicTheMx5]

I'll reword my question a little bit:

Does the ideal oil temp for a BP engine change depending on what type of oil you use?

I know there are a lot of people with oil temp gauges on here, so what numbers do you typically see?

Thanks

[greenMachine]

What use? Racecar?

What was it running before you put the cooler in? Under what circumstances?

There is no ideal oil temp for a BP. There may be an ideal oil temp for that oil, what does the PDS say? What does your engine builder say? Mechanic?

We can guess as well as you, and probably BS better. You need to tell us more, so we can give our collective wisdom ... or something

[Cus]

The video I posted the other day just here mentions around 100degC for the brand of oil being referred to.

The thread 93_Clubman links to in that same thread goes into way, way WAY more detail, read that too ;)

[NicTheMx5]

I know there are a lot of people with oil temp gauges on here, so what numbers do you typically see?

Just curious about that really.
I understand different oils will have different temps, that's why I'm asking what the average might be.

[NitroDann]

Rule of thumb is 10*c higher than water temp, and the rule of thumb for water temp is 80-85*c.

But you didnt ask that, you asked something that the manufacturer of your oil specifies. So you need to find out from them. Whether you call their 1800 number or google the PDS as has been suggested, the ideal oil temp depends on the oil itself, not the car.

Dann

[ManiacLachy]

Rule of thumb is 10*c higher than water temp, and the rule of thumb for water temp is 80-85*c.

You've got me worried about my water temp now. I see 92-98 on the daily drive

[RS2000]

Rule of thumb is 10*c higher than water temp, and the rule of thumb for water temp is 80-85*c.

You've got me worried about my water temp now. I see 92-98 on the daily drive

I wouldn't worry. The NB Mazda factory manual states - thermostat opening temp 83-88 deg C & fully open temp 100 deg C.

[Magpie]

The question should be have you selected the right oil for the engines use...

I have used HKS SUPER RACING 10w55 Max. Oil Temp. 150℃ (100％ SYNTHETIC SM-CF equivalent), now use a Martini equivalent.

The viscosity of the oil changes with temperature and at higher temperatures this can result in frictional losses (higher wear).

Castrol edge 5w40
Viscosity, Kinematic 100C - 14.0
Viscosity, Kinematic 40C - 84
Viscosity index - 172

Castrol edge 0w40
Viscosity, Kinematic 100C - 13.1
Viscosity, Kinematic 40C - 77.1
Viscosity index - 172

Magnatec Professional C3 5W-40
Viscosity, Kinematic 100C - 13.4
Viscosity, Kinematic 40C - 81
Viscosity index - 169

The lower the viscosity index the more drop in viscosity as the oil warms up, a higher viscosity index the less drop in viscosity as the oil warms up. The higher the viscosity index the less drop in viscosity as the engine warms up.

Now if you are seeing less than the temperature that the oil is tested at (100°c) then you do not have a 40 SAE rated oil...

So the answer to your question is if you want the SAE of the oil to match what you have purchased then it needs to be at the temperature it was tested at 100°c. What is the oil pressure reading in the car?

My data logging shows that on the track my oil temperature tops at around 98°c with water at about 95°c, this excludes heat soak...

Did this a while ago, comparing oil pressure to temperature and you can see the trend with lower oil pressure over time due to heat soak.
MP_Oil_Temp by Eipeip, on Flickr

[StillIC]

.....Cool down! (pun intended )......

Sorry Ed, it was a perfect storm of pet hates coming together as one. I have cooled down now, but my pet hates remain. I would love to see more oil companies publish data about their products. I would love not to have individuals contact large corporations to find out basic data about products. I would love for all information flow to be 'few to many' not 'many to few'. I would love the expectation for information to be on the wealthy 'for profit' provider, not the less wealthy individual consumer. I could go on!

[StillIC]

Of interest to all, I recently trawled the web for all sorts of information regarding optimal oil temperatures. I have plotted ranges graphically comparing what one or two oil manufacturers say versus what engine builders suggest. From this I have come to very few conclusions.

For the sake of the engine a number of engine builders (not oil manufacturers) suggest that oil run hotter than 100C to fully evaporate any condensation and burn off, ummmm, whatever deposits they need to burn off (seems dodgy). The 100C makes sense to ensure the water boils, but I reckon most of it would be vapourised by 100C anyway. But what would I know!

It seems most oils will start breaking down on the hot side of 125C, so, even though some oils might be able to run hotter, this seems like a reasonable upper limit for most applications. And that, people, defines the range that I try to stay in.....quite often unsuccessfully.

[Magpie]

Actually they give data on flash point of the oil, from memory it was around 200°c. However if the block gets to 200°c I would expect other issues to surface.

In general letting the oil get above 125°c would not be recommended. The data available suggests that the viscosity for most oils would be about 3 at about 125°c (generally speaking) and this would offer very little protection to the engine. However you would start to see issues with oil pressure if the oil thinned out that much. Do you have an oil pressure gauge?