There are a few points which need addressing, but overall I think the article was interesting and informative ...
- The oil temp does not "double", technically. We presume it does because of the Fahrenheit scale, but in terms of true thermal energy (based on the Kelvin scale), the oil temp does not "double". Even if you used Celcius, the temp does not "double". It only doubles because it was measured in Fahrenheit. When engineers truly calculate thermal energy transfer, it's typically done in Kelvin to properly account for expansion. This is a common misunderstanding and misapplication of thermodynamic laws. In this article, the stated conditions produced the following "temp" changes. Note that I round to the nearest whole integer:
80F to 160F (exact double)
27C to 71C (more than doubles)
300K to 344K (less than doubles)
- There is validity in the topic of how the flow rate changes with the temps. But this really can't be fresh news to any of us, can it? This is why sumps are (or at least should be) sized for the varied expectations of applications. In this case, it was a racing application. But the same holds true for "normal" cars, trucks, tractors, motorcycles, etc ... There is a known volume of oil needed to account for the variance of drainback from cold to hot operational conditions. There also needs to be a min specific volume of the sump in terms of physical holding capacity so that undesirable events don't occur. Kind of like Goldie Locks; too much or too little isn't good.
- Obviously (at least to most of us), this set of data only applies to the specific oil used under those conditions. There will be a different response curve for different lubes ... 15w-40 isn't going to flow the same as 5w-20, for those stated test parameters, etc.
The article is interesting and informative, but I fear the common BITOGer is going to take that info and run with it, assuming it applies to all lubes at all times, and that's flat out wrong. It does a good job of illuminating the concept of oil flow changing with temps, but it's NOT to be considered a one-size-fits-all engineering answer.