Ok I have been reading posts on fuel temperature effecting the vp44.No one is saying what is a good temperature for the fuel!How hot is to hot?How cold is to cold?If the overflow valve is not allowing fuel to return to the tank then you are stuck with the temperature that is coming from the tank.If the overflow valve is open then the temperature is what is generated under the hood and from friction in the pump and injector pump!So would a inline cooler be a improvement? then if the air is to cold it seems like it would be a detrament and you would want a inline heater.Just some thoughts in my head and I would like to see other peoples thought on this

Well I can tell you that if the fuel is below 60-70*F the fuel heater is running... As for fuel temp there is a error code for overheated fuel... I've never seen 1 report of this code yet...

P0180 FUEL INJECTION PUMP TEMPERATURE OUT OF RANGE

From the service manual. When the temperature is below 45 ±8 degrees F, the temperature sensor allows current to flow to the heater elementwarming the fuel. When the temperature is above 75 ±8 degrees F, the sensor stops current flow to the heaterelement.I would think if your getting hot fuel in the summer a cooler may not be bad, but you would want to bypass it in the winter. I am wanting to add another heater to my first filter, Fleetguard makes a 300w 1-14 sandwich heater with the same thermostat at the OE heater.

Reading this post, when I installed the air dog 100 I went straight the 44,bypassed the heater. I haven't not noticed any problems in the winter, at 4800 ft. So should install some type of heat for the fuel? What would you look for in problems, sorry about jumping in.