My Oil Temp Experiment

[JHZR2]

My test:

2011 BMW 135i, 300hp twin turbo, N55 engine, MT
Gentle driving, stoplights and 45MPH driving. Including drive over Walt Whitman Bridge (2-3 miles uphill then downhill) partway through trip.
Oil temp from gauge, water temp from scangauge
Ambient temp, 68F.
Code:


Miles on trip Water T Oil T

146.5 71

146.6 100

147 124

147.5 157

147.7 165 first budge

148 172

148.5 182

149 195

149.2 200

149.5 206 first tick

150 216

150.2 216 2nd tick

150.5 220

150.5 220 3rd tick

151.6 220 4th tick

152.4 224

152.9 224 5th tick

153.6 220 6th tick

154.8 216 7th tick (full temp)

 

[zoomzoom]

from the experience in my s4 oil temperature will lag coolant temps by about 6 minutes at highway speeds..regardless of the outside temperature.

 

[SteveSRT8]

This is extremely relative to the design of your engine.

Most engines with piston cooling oil jets will heat up very fast compared with those that don't.

Also depends on sump volume.

 

[Slippery_Pete]

It's neat to see how much longer the oil takes to warm up.
Thanks for posting.

 

[Quattro Pete]

Do you know what specific temperatures the different "ticks" on the oil gauge refer to?

 

[JHZR2]

Originally Posted By: SteveSRT8
This is extremely relative to the design of your engine.

Most engines with piston cooling oil jets will heat up very fast compared with those that don't.

Also depends on sump volume.


Well of course it does, thus why I gave the information that I did.

Still, it gives some insight that folks don't usually have.



Originally Posted By: Quattro Pete
Do you know what specific temperatures the different "ticks" on the oil gauge refer to?


I do/can but don't have it off the top of my head... Will need to post later.

 

[Jim 5]

What do you mean "Twin Turbo N55"?

 

[JHZR2]

It is really a twin scroll, single housing engine. N55 is the engine designator that tells you everything about it.

 

[Jim 5]

Originally Posted By: JHZR2
It is really a twin scroll, single housing engine. N55 is the engine designator that tells you everything about it.


Just giving you the gears. I found BMW's nomenclature funny when they went to the single turbo. I'm in the market for one of these hopefully soon.

 

[antonmnster]

I see with the household A6 that the oil temp seriously lags the coolant temp.

It also fluctuates with ambient temp and engine load. A 75 mph run in 90 degree weather will send the oil up to 250F; around-town at the same temp and the cooling fans will be running all the time but the oil temp doesn't go over 200.

Interesting stuff.

 

[Jim 5]

"Shanneba" who used to post on this site at one point posted a very detailed data log showing coolant temp against oil temp and mileage measured I think every 30 seconds for a period of 20 minutes.

His car I think was a 2000 BMW 328ci and his chart data aligned with yours in the sense that the coolant heated up rather quickly, but the oil temperature lagged behind significantly. IIRC his oil temp lagged longer than yours which makes sense given that your oil is cooling the turbo and your car has a significantly greater power density than his did. The sump on your car should have been about the same as yours.

 

[Steve S]

Load has all to do with the oil temps as well as design.

 

[CBR.worm]

My dad has a porsche cayenne S with a decent size V8. It takes many miles for the oil temp to come up to 200f. Probably more than 15 miles, the coolant temp comes up very quickly. i don't know much about his engine other than it is a strong 32 valve 4 cam V8.

Being a Porsche it probably holds a lot of oil.

It was a real eye opener for my, I was someone who used to think that once the coolant temp gauge was up, you were good to go.