I've had a fuel heater in my car for about 2 months now. Hard to say what the benefit is though since I have no "scientific data" to show anything. I do too many modifications at one time so it's hard to tell what each mod nets me.
I tapped into my coolant line and rerouted it down the fuel rail, wrapping it up against the fuel line. No extra power needed, just a longer coolant hose. I didn't want to mess with actually splicing into a fuel line (dont' like the idea of blowing myself up...)
From hooking up a probe thermometer, I've seen the temperature rise about 20F when the car is warmed up.
__________________
|