another reason to use an electric fan is that if you plan on doing deep water crossings an electric fan can be switched off prior to diving in while a mechanical fan will keep spinning. If a mechanical fan impacts the water while spinning it can get pushed into the radiator. This is generally considered a bad outcome. Other than this mechanical fans are less maintenance and usually trouble free. I had two electric fans on my V8 powered 85' extra cab pickup. It worked well and always kept the motor cool, but I wanted to use two, so that I would still have one functioning if the other died.
