Stillen states:
"An oil temperature reduction of 30 to 40 degrees Fahrenheit can be realized with the installation of our specially designed Oil Cooler Kits. These Oil Cooler Kits allow hot oil to be circulated and cooled outside of the motor through a high efficiency cooler.
Thousands of miles of engine life will be added by keeping a "cool" coating of oil on high-wear engine components such as piston rings, piston skirts, cam bearings, and rod bearings."
But I found on another forum:
"Our stock oil cooler is a step up from the standard run of the mill radiator. We have a special system that actually routes engine coolant to pull heat out of the oil. It allegedly lowers temperatures about 10 F than without it. In addition, it also helps warm the oil up in the winter because the engine coolant warms up faster than the oil.
That said, an extra cooler is not necessary unless you have boost or you tow 7,000+ pounds on a regular basis."
Obviously, the Flex-a-Lite version is a no brainer compared with Stillen's $500 offer. But if neither one is going to cool my oil significantly more than my stock one, there's no need unless failure occurs.