Wish I had a Scangauge years ago...
 

The scangauge is a great tool! Its showing me some interesting things besides the obvious best speeds to drive at for higher FE.

-Driving on roads that have 3mm standing water really eats into your FE! I often see 6mpg drop that can last for miles? Time to pick a better road when its raining heavy. What can I say, Louisiana roads are terrible...

-When your roof rack is literally whistling in the breeze its likely costing you FE.. Yep I removed the roof rack and it looks like it was good for 1.5mpg at speed. Nice!

-My engine is not getting warmed up near fast enough especially in the morning. Looks like 190F is where it eventually controls at if you drive long enough. Now in the morning all it ever gets too is 186F. I really can see a difference in FE when its running under 190F. I think what?s happening here is the radiator is over cooling the water keeping a good portion of the engine running too cool. I?ve got a thermostatic fan clutch so its pulling air at all times. One morning I ran the A/C for a short time to help heat the water then shut it off and sure enough the steady state mileage numbers jumped up to the range where there supposed to be when fully heated.
I?m really thinking about an electric fan conversion? Next thing I?m going to try is block off the bumper air intakes and see what that does?

Last fill up was 25.3mpg, not to shabby for a EPA combined 18mpg truck!

Gratz on the FE jump ! I am amazed at the increases that the truck folk get - I've had two myself and never could get the bump like I'm seeing here . Quite an accomplishment!

IFE *is* the greatest thing since sliced bread idd'nit ? You really 'see' what you are achieving and know what works right away .

Good information. I've often wondered how much standing water effected FE.

I would recommend blocking off the upper grill and leaving the bumper air intakes open. I would also get an electric fan for the radiator.

I would try the grill block and maybe some of the bumper air intakes block, first, as far as engine temperature goes, before you change something. I suspect your thermostat is probably starting to open at around 186 and the air which is being pulled through the radiator, right now, is what is keeping it from getting up the last 4 degrees.

iirc ridge riding gets you out of the wear ruts in the road and helps keep you from plowing through rain water (or light snow for us northerners).

Good thinking. The far right lane on the interstate has deep ruts from all the semi's, but you'd have to see if your car is wide enough to run the ridges,,,

I try to run on the ridges in the road but its a narrow two lane road with no shoulders.. It puts me almost in the ditch or into oncoming traffic so now I just avoid that route when its raining..

Oh yea! I used to run whole tanks trying a specific driving style to see what works better.. Thats like working with "Stone knives and bearskins". :D

The lower bumper looks to be way easer to block from the back side so thats they way I'm going first. Also in states with front plates it would block over half the bumper inlet so I think its mostly for show...

I had looked up the thermostat specs in my Toyota service manual and it has the thermostat fully closed at 104F, opening between 176-183F and a valve lift of 8.5mm or more at 203F. So I was thinking it seems to be in the ball park but I need to do some checking to see if its leaking to bad.
I have an IR thermometer but have not checked what the radiator differential temp is nor the engine outlet. Its on the list of things to do. From some internet sources I found the radiator is only supposed to drop the water about 10F so thats another thing I want to look at.

I need to find an old Ford Tarus fan or a Mark VIII. Going to call some junk yards after the 4th.

Wow - 25.3 mpg- excellent for something rated 18!

Only 186 deg showing on ScanGauge?

Replace your thermostat. Try learn what's oem spec and get one rated that temp, or maybe hotter. T'stats can lose their calibration over time and not keep things at the intended temperature. Also an independent shop may well have replaced the original with one calibrated for another temperature.

Yes - grill block and other things can help but the t'stat is supposed to get the engine to proper temp and keep it there.

Try FPS in Atlanta for Ford stuff . He may know right off where/who in your area has one if he doesn't have it himself .

I have a lofty goal of 30mpg, but realistically I think maybe around 28mpg eventually.

Yep thats a ScanGauge temp reading. It never goes above 190F even towing my boat. Towing I get 14.5mpg at 55mph with overdrive off.

Its the original thermostat. I'm right at 50k miles so its about time to do the coolant and stat anyway I suppose.

Thanks, but I'm gonna give the local junk yards a try first since I think the shipping would be nearly as much as the fan. That and I'd like to have an up close and personal look at the fan.

Replaced the engine coolant today and the thermostat for good measure. After having a few thermostats fail on me years ago I started replacing them every 50k miles so it was time. Anyway the new one works about like the old one.
Turns out the thermostat is stamped 82c and thats right at 180F so it explains why is runs a bit cool. The new thermostat will get up to 190F on the ScanGauge but no more...

One thing thats a seems a bit odd about the thermostats location on what I would normally think as the cool water inlet! What I'm saying is the cool water enters directly on top of the thermostat which just seems just completely wrong but thats the way its made.

I checked the radiator lines with an IR thermometer and the hottest line is the upper line on the radiator, 175F while the lower line going to the port where the thermostat is only 115F. Perhaps the system has an internal circulation thats keeping the whole block at about the same temp?

Blocked the lower intake with black clorplast from a local sign shop. It did not seem to have any real affect at getting the engine up to temp quicker. Theres still plenty of open grill though, but since I tow often I'm not comfortable with blocking any more off..
Anyway I did see at least a few tenths or maybe a good bit more difference on the few miles I drive at 65mph highway speeds. It was hard to tell today to be sure I was not seeing any draft affecting the numbers.
At 48mph I could not see any difference at all. 48mph is the magic number where the TC locks up in high gear and I run there a good bit. Still need to get some more miles at highway speeds to really know for sure.


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