2012 Invention Awards: A Higher-Efficiency, Lower-Emission Engine System | Popular Science
Read the above (URL) article in PopSci magazine June issue. An engineer won an award for his invention that does the complete opposite of what oil coolers do in our cars! This device or mod collects the hot motor oil before it returns to the oil pan and sends it to a heat exchanger that transfers heat from the engine's exhaust gas making the oil even hotter. Thereby, it continuously keeps the oil temperature high between 250F and 300F degrees, while the engine block remains at 200F. The article seems to imply that the less viscous and hotter oil increases the engine efficiency and reduces emission because it is easier to turn the crankshaft and run the oil pump. It claims that the system would cut the gas consumption by 7% and emission by 30%.
So perhaps this reiterates that there was a method to Nissan's madness in designing an engine that runs oil at very high temperatures?
However, wouldn't a 250-300F degree oil, in turn heat up the engine block above 200F or put too much strain on the coolant system? It may decrease the gas consumption and emission but the big open question is still the longevity of the engine components? Not sure if there is any gain in horsepower o/p because it is easier to turn the components in the engine? Also, if it is as simple as less viscous oil providing less resistance in the engine, why not change the type of the oil to a less viscous oil? A few things seem contrary to conventional wisdom here, so I thought I would post this and get your thoughts....