EXCURSIONATOR1 , I have checked the color in the tail pipe and it doesn't look very bad kind of a lite brown.

Downsea ; My truck has manaul hubs and 4x4 transfer case, doesn't see 4x4 very often.

i have a 99 f250 with a 4" lift, 35s, stock gearing, custom exhaust and a superchip programmer installed and i get around 12 in town and around 15 or 16 on the highway

9-12 in town and 15-16 on highway. max highway has been 16.2 at 70, 2k rpm

10-12 mostly mixed between highway and city best I ever had was 13. Worst was less than 9 and needed a tune-up back up to 12 in the summer and 10 in the winter.

8-9 on country hwy

I'm getting a solid 14 to 15 highway mpg. I have a 5 speed with 3.73s 6 inch lift n 35s. Has custom cold air intake and true duals with 18inch glasspacks

https://www.ford-trucks.com/forums/p...ictureid=60054

Dad's 06 F250 CC 3.73 gears with 5.4 and manuel has been getting around 8mpg to 10mpg at the most around town. Gets a little better driving the river but not much better maybe 12mpg.
Even the V10's and my 460 get better than it.lol

Has anyone tried running electric fans to improve mpg? And as far as things needing improvement on these engines in the SD's so far I keep seeing headers, y-pipe and exahaust. the air intake on these trucks seems to work as well as any of the aftermarket replacements. What about camper shells has anyone tried that? There not cheap but neither is bad gas milage.

i thought about it on my 04 as i would have to imagine the engine would love to not have to lug that thing around anymore...but i don't think the electric fans don't work for cooling well when the truck is working...

The f-fan kit that I fabricated for the Navigator worked well-even when towing our 33' travel trailer. That Navigator would have no more heat load than a Superduty with a 5.4L since it's got the same 4R100 trans and a 5.4L, so it's a good comparison. I wouldn't use one for a 6.8L or a diesel-I dunno if the fan can keep up to those 2 engines due to the increased heat load. But for a 5.4L, I wouldn't hesitate to use an e-fan. The Superduty would likely be more suited for an e-fan since it has a radiator with a larger surface are for better heat rejection than the Navigator.
JL

Freeway (70 mph) 19.5-21 (with a/c on, drops about .5 to 1 mpg)
City (easy driving) 15
heavy traffic city- 13

WOW! That needs a little more detail.

I tried electric fans,they worked well in the winter colder months. I had to reinstall the mechannical fan once temps got above 80

What brand and type?
JL

Thanks Johnny for the feedback. You said you fabricated one for your navigator; did you use one fan or two? Also, did you build a shroud for the fan(s) or did you just bolt them on the back/front of the radiator?
If you’re willing to show off your work with some pictures that would be of great help to me.
What kind of increase in power and/or mileage did you notice?
when the fans kick on do you notice any draw on the electrical system? Your dash lights don't dim or anything do they?

Flex-a-lite sells a two fan bolt on kit for the f-250 that claims to move 4000cfm, but it does not use a shroud. I’m thinking that kit would be a good starting point but before I bet 600$ that it will work I would like to get as much information as possible.

If any of you guys know where I can find the answers to any of these questions I would really appreciate it.
Thanks,

How many CFM does the stock fan move?


Any suggestions about using OEM fans off of other vehicles or fans that may be used for other purposes than automotive?

Any suggestions on ways to build the shroud itself?
Plastic?
Fiberglass?
Sheet metal?