I've added fans to my factory fuel cooler and also added another cooler in front of the radiator to gain any benefits I can from cooler fuel. It's the factory cooler, which Mike has pointed out is not nearly as efficient as his probably is. To be honest, I never noticed an appreciable gain in mileage. I never did monitor my fuel temps after adding the front cooler. Maybe one of these days I'll do a before and after test and report back.
To add a cooler up front is relatively simple. I had an old transmission cooler with 3/8 (I think) hose ends, bought male and female quick disconnects and about 12 foot of fuel injection fuel line. I disconnected the return line and used the new disconnects to insert the front mounted cooler. You can run the lines along side the radiator , no problem.
With a single cp3, there is very little pressure in the return line.