Ive seen this on Diesel engines which do a lot of regens. Also the car may ask for the oil to be changed when it reaches a certain quality level.
That is one thing I find it does do quite a few regens, I notice it when I have done a slower drive (sitting at about 60 on a 30 mile journey) and at the end it keeps the fan on and it sticks like burning rubber. But if I give it a spirited drive I don't get this.
How can it detect the quality of the oil?