I check my oil when it is cold to allow the oil to fully drain out of the oil dipstick tube so that I can clearly see the level. As the temperatures are getting colder, I have noticed a drop in my oil level. I searched the internet for the change in volume due to temperature for sythetic oil. I found the following post from the Chysler Sebring/200 Convertible Club. The change can be quite signicant and should be taken into account when checking the oil when cold.


Author: EJS [ Sat May 15, 2010 8:02 pm ]Post subject: Re: Fully Synthetic Oil, How much does it Expand ?For what's its worth----
I found these two tidbits in different places while poking around for info about thermal expansion of motor oil.

°F - °C - Density - Vol in ltrs - Vol change %
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59 - 15 - 0.858 - 4.00 - 0.00
68 - 20 - 0.855 - 4.01 - 0.35
104 - 40 - 0.842 - 4.08 - 1.90
140 - 60 - 0,828 - 4.14 - 3.62
176 - 80 - 0.815 - 4.21 - 5.28
212 - 100 - 0.802 - 4.28 - 6.98
248 - 120 - 0.789 - 4.35 - 8.75
284 - 140 - 0.776 - 4.42 - 10.57

This is an example of a 5W-40 oil

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0.0004 / degree F, so for a 120 degree F delta-T you get a 4.8% change in volume
Author: bigotter [ Sun May 16, 2010 8:58 am ]Post subject: Re: Fully Synthetic Oil, How much does it Expand ?There's your answer, EJS's chart proves it!! From 59 degrees F to 212 degrees F there's an increase in volume, oil goes from 4.0 L to 4.28L... that volumetric expansion should equate to the difference on your dip stick, hmmmm learn some thing new every day!!

Morris, 2011 MC, PW/B

 

R56 dip stick can be a PITA to read. Maybe check out the replacement one by Craven Speed so you can check oil level when hot as recomended by MINI.

Craven Speed Dip Sticks

 

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Great info!