The reason I got the oil cooler was because i will be running nitrous.
I heard the optimal oil temp for a zetec was ~180 degrees.
Would be a good question for Terry Haines.
I haven't noticed any performance gain or drop.
But the car idles much smoother now.
I have a simple switch connected to the fan.
I would have to go look at my notes for exact wiring points.
The on position of the switch cuts the power line before the fan switch and supplies it to directly to the fan.
The oil filter fitting for a zetec is a 1/2".
The kit comes with a 5/8".