I have only had my Ultra Cool oil cooler on my 2011 Road King for two weeks and I have seen an improvement in the engine operating temperature in 80 to 90 degree temperatures. The engine runs cooler during highway driving as well as during stop and go traffic. When the fans come on the system reduces the oil temperature to the point where the oil drops down to 190 degrees and the fans shut down. This is the best thing I could have done for my Harley in the Florida weather.