Here's my question. Are there any studies out there comparing the longevity/reliability of an engine that has an oil cooler installed verses one that doesn't, all other things being equal? I run quality synthetics in my crankcase and tranny while running HD Formula + in the primary and I have Xieds installed to richen up the AFR. This is on my stock 96" with factory exhaust and no stage 1. From everything I've read an oil cooler will lower the oil temp around 25*, not really noticeable to the rider. Would that 25* really make a difference to the life of the engine?? I ask because I want an oil cooler but am hesitant to buy one because of the expense. Thanx. I deliberately did NOT state what type synthetic I run because I do not want to turn this into an oil debate. There are plenty of threads on that. I am looking for hard evidence that an oil cooler will extend the life of the engine.