I guess my question is which reading are you going off of? if you use the Cylinder head temp it will be more accurate on the exact temp because it has a sensor, but the other setting, ECT i think is what it shows, is derived from the CHT. so you might be getting what you want without realizing it :)

Thats an excellent point I never considered. The CHT sit arounc 200-205 usually. Maybe I'll get one of those infared temp guns and see what the actual rad temp is. Longshot had said Jacks truck runs routinely around this temp but I thought he was refering to ECT not CHT though the two are directly related. Infact if I have both set to display at the same time they will show almost the same reading and climb at the same rate up to about
190 F then CHT continues to climb to the low 200s as the thermostat opens.

i.ve got dual shrouded 16" fans (5000cfm total), ford racing rad, and 180* t-stat. fan controller is set to turn on at 200*ECT (~205*CHT). with this combo i can sit in traffic all day with the fans only kicking on every 5 minutes or so (run 15-30sec and cut off). when i'm moving, CHT never goes over 190* with the fans off, 185* if i turn them on via override switch. (only did once to test)

Sounds like that combo works great. It's pretty similar to what I'm considering from FF Dynamics. I'm gonna do this mod most likely in the spring, but it sounds like I have nothing to worry about with dual 16" 6000cfm total rating fans. Do you have your fans set to come on with the AC?? Did you notice performance improvements with the installation of the e-fans??

yes, if they aren't already running they turn on at 50% power for AC. it definitely revs up faster, MPG was the biggest increase.

Thats awesome. I'm definitely looking forward to the MPG and performance improvements!!

Read on the f150Forum that on 4.6 it does not increase MPG or HP.
But on the 5.4 some said you will get 20-30 more mpg per tank, which is like 0.7-1.1mpg increase.
I am guessing this will only be in the summer time though when you do use your AC.
And as for the HP increase with 5.4, I doubt it would be anything noticeable, all it is doing is freeing up a clutch.
The biggest outcome from this would be to lessen the miles on your water pump.
I would spend no more than 200 on a total setup.

I do plan on doing this mod tho on my 5.4

I'm looking at about $275 with the setup I plan to get. I'm ok with that amount, as it seems to be a quality kit that I can rely on. I'll most likely drop in some UD pulleys at the same time, so hopefully I'll notice a little more HP increase by doing the two mods together rather than just the e-fan upgrade.

I've decided that it is not the temp setting of the efan that is causing my low coolant temp. I pulled the fuse for the fan today and am still getting temps in the low 190s. I'm now thinking that my themostat is actually stuck partially open or is a cooler thermostat then is supposed to be in there I'm going to switch it out for a new one tomorow.

I'm fairly certain the stock thermostat is a 195 degree one. I personally would not use one colder than that. The engines are designed to operate in the low 200 degree region, and yes, when I'm just driving my truck on the highway in our "fall" temperatures in the high 80s, the CHT tends to stabilize around 205 degrees.

- Jack