'05 Efans & 160* T-stat MPG decrease?
 

Title says it.
Is that possible? Ya, I know it's gettin colder out, but I changed nothin else that comes to mind. But I did both fans/ stat at same time, so IDK if it's the cooler T-stat, the fans running instead of clutch fan or lowering fan on/ off temps?

Any ideas?

My truck doesn't go over 185* since efans install.

I'm considering raising my fans on temp / off temp to see if that helps.

A couple of things come to mind on this. A colder running engine uses more fuel. More fuel = more power(usually). This is one reason people use colder t-stats. Also, winter fuels aren't the same as summer fuels, and fuel mileage decreases. Also, with colder weather, we tend to let our vehicles warm up longer before driving. Also, colder winter air is denser, so the engine will use more fuel.

I don't think it has anything at all to do with your e-fans, or their settings. If anything, the e-fans should be helping your mileage, even during winter. They may never even come on during cold days. Certainly not as much parasitic draw as a clutch fan.

During the summer, I can go 450 miles on a tank. During the winter, it drops to 350 miles.

You need to adjust the tune for the 160 degree thermostat. Right now additional fuel is being added to help the motor get up to operating temperature, only thing is it is never going to get up to what it thinks operating temperature is supposed to be and will continue to add fuel. You will probably notice your exhaust tip being sooted up.

Usually, about the coldest you can go on thermostats without changing the tune is a 185 degree unit.

x2 on the winter mileage going down. probably cuz it takes longer to warm up.

Ya, it seems peppier. So I'm thinkin it has more power. I never did a 0-30, 0-60 & 1/4 mi beforehand. I'm normally more methodical when I do a mod. I try to do 1 @ a time. Then see results. But my tranny has me worried, so I'm tryin to stay away from strip & dyno. Trans is another story.

I know they're comin on. In fact, at night w/. lights, radio & heat on it'll take voltmeter down to under the middle hash mark. I forgot what voltage that would be. It's factory battery, alt, & pulley. All just over 5 yrs old.

I bought a alt. pulley from Blackbear to run on my stock alt. I never popped it on cause I wanted to see how it'd be w/o it. I didn't know if volt drop is causin PCM to manipulate RPMS w/o me noticing. I haven't hooked up HPT to confirm, but just have looked at last few fillups as a gauge (no pun intended).

My RCSB couldn't get 450 mi from a tank if I wanted. Plus, I think it's only a 26 gal tank.

Didn't change tune except fan settings. :hmmm: Since I wouldn't know where to change since all I've tweaked is speedo adjust for bigger rear tires, fans, & DTCs, I think that is beyond me at this time.

Could a timing increase by say 1* or 1.5* play nice w/. the cooler stat to bring MPG back inline?

Ya, it ran rich before, as all trucks do run fat from factory for preservation. Now, it's prolly worse than before by what you're sayin. Man, I shoulda had my W/B on there before. Now, I could have noted the change. Now, the control or baseline is pretty much gone, huh?
Sounds like I should get mywide band to monitor, & now even more so.

Do they use RFG in TX? I'm not sure when they start here.

It's the winter fuel blend. My MPG got any worse.

BTW, I didn't notice barely any power gain from the Efans. Probably more hassle and wasted money than it's worth in retrospect

I thought at 1st you said it didn't seem any faster, then later, felt an improvement. What do u feel is wasted $ or hassle? I'll admit, those factory hose clamps are a pain! :bang: And some mistakes that slowed the job, but I know how to do quicker if I had to do it again. So, I learned something.
Is it the pinouts that bothered you or tuning?
Cause, honestly the pinouts were the main thing that concerned me. I just watched how pins are done by a pro. The messy part is coolant comin out of hoses, outta water pump & onto ground. At least u didn't have to do water pump gaskets. :D

It woulda gone faster for me had I not had to do w/. stiff neck/ upper back issues. Every once in awhile, u get lucky & help shows up when u least expect. :angel::biggrinan

I figure I got ~$360 into it between the '05 fans from a yard, bigger rad, Blackbear harness & pulley (that I left off for now, but may put on still) & my 160* stat.
My favorite part was help from 2 bros her & there, my best friend on harness pinout, & it cleans up the engine bay w/. even more room.

the install wasn't a problem. But now I do need a 145 amp alt. I haven't realized any MPG gain with the efans. And power, like I said, it's a very very slight gain if at all.

Any idea on how low your volts are goin down to? Sounds similiar to what I have goin on. I forgot how low it drops to exactly, but at least to hash mark I mentioned earlier. I'm almost afraid to be stopped w/. radio, lights, & heat on "HI" while fans run, cause I already see what it does on blower setting "1".

Free fix for me:install that pulley. Option 2:For me to get a 145A alt. as well. I checked @ yard when I got fans. Said I'll come back if needbe. I'm guessin $40 at least to do that route.