[Daox]

One of the MirageForum members just eased my mind about the oil warmer also being a oil cooler. He does have the 1.0L, but I don't see that making a big difference. Here is his test data:

Since my 1.0L stripped-naked MT model has practically no instruments other than speedo and fuel level, I wanted to do a few measurements of water and oil temperature, purely out of curiosity.

The following readings were taken with two thermometers, one on the upper region of, and directly on the cylinder head, and the other one directly on the oilfilter. For sake of getting an accurate reading, the area around each sensor was additionally padded or wrapped with a rag, with each sensor directly touching the metal.

Conditions: Temperatures taken with a 3/4 grille block, after more than an hour's drive on the highway at normal speed and 24-26°C outside temperature, car has roughly 60 000km and 0W20 oil with ILSAC GF-5 classification. The measurements were verified by swapping and repositioning both sensors and rereading the temperature some time and some kilometers later.

I measured a cylinder head (water) temperature of 89°C (thermostat opens 87°C), and an oil temperature of only 78°C.
What surprised me most was the modest oil temperature, much lower than with similar sized cars and highway conditions. With that sort of oil temperature, we can expect the bearings and oil seals to last a long time.