I'll be a fun project for some

[SilveradoMike]

Unfortunatly replacing the shell isnt in the cards. The height of the current one is barley tall enough for my cargo. I think I may try the "wing" Ill test a few designs with foam then Ill fiberglass one up when I get some measureable positive results. I think its amazing how coasting in neutral will make it instant mpg shoots up over 100mpg. You think a 1/8" steel under tray/skid plate would make a measureable gain? Maybe another slightly less then 1 mpg? I would imagine it would be in the 300lb range for weight. On a partial grill block. My engine coolant temp is already 195°f not really looking to raise it to much more. I get the aero positives of it but how much would you think it will raise temos? I know it varies with different parameters but lets just say for this we're on hilly terrain average speed about 35mph max maybe 60mph coolant temp 195°f.

[wmjinman]

Ok, so yeah - try to build a deflector. But please do "A-B-A testing" with your ScanGauge. Otherwise, it'll be VERY difficult to determine for sure if it's working at all. Read MetroMPG's guide on A-B-A testing under the "EcoModding Central" area. That method works really well, and will tell you for sure if your mod is "working" or not. If you get "inconclusive results", and you're testing it correctly, then it's not helping enough to matter.

I think a 1/8th inch steel belly pan would be too heavy (and trouble to make)to be worthwhile. If you're going to do it, use something lighter (thinner sheetmetal, aluminum, composite, - - -). A simpler approach might be to do an air dam. Does your truck have a factory air dam, and if so, does it extend far enough down that it's as low as all of the other "junk" hanging down (differentials, etc)? If not, building an air dam, or extending it, down to where it's as low as the lowest hanging stuff underneath will help a lot. While you're at it, try to contour the sides so they also deflect the air around the front tires. You would probably get more "bang for the buck" with this than a 1/8" steel belly pan.

From what I pick up on here, grille openings are designed oversize so there's enough air for ANY occasion (I read that to mean towing an Airstream trailer up the mountains out of Death Valley in the summertime with the A/C on!!!) So, there is certainly an opportunity to block your grille some (probably over 50%) without hurting your temp. (unless you're pulling aforesaid trailer out of Death Valley in the summer). You can set your ScanGauge to read water temp, and when fooling around with grille blocking, it's highly recommended to do that & monitor it closely. On my 2000 Jimmy (4.3 liter, auto tranny, 4wd), I think I picked up 1.4 MPG by blocking the grille. At first, I blocked it all the way, and it DID overheat. So I cut a hole in it (just used cardboard to experiment) and that helped. Later on, I decided to enlarge the hole (to 6.25" diameter), and that did the trick - no more overheating after that. Likewise, if you're not too worried about it looking too "Jethro redneck", why not experiment with cardboard & duct tape? Easy, effective, and will tell you the story in A-B-A testing with the ScanGauge.

If you click on the "Jimmy" under my name in the column on the left, you can see a picture of what I did.

[War_Wagon]

Welcome. Not sure if you have done this already, but synthetic oil at your next oil change might be a consideration. Two differentials, a transmission, and a transfer case all spinning makes for a lot of sources of friction, you may consider servicing them with synthetic fluids next time they are due as well. Being a regular cab with a 5 speed, I am guessing your truck has steel wheels, not alloys. If your windy rural driving has a lot of stops, finding some used factory alloys might be something to look at. Reducing your un-sprung rotational mass would help with a lot of stop & go driving. Used factory alloy wheels are probably fairly inexpensive, being the first thing someone usually takes off when they decide to mod their 4x4.

[wmjinman]

Just picked up almost 2.5 MPG in my Suzuki Swift by doing a simple grille block out of duct tape. 3 set 2-way average before was 46.95 MPG, and with the grille bock came out at 49.41, an improvement of 2.467 MPG.

So I'm now more convinced than ever that a grille block is about the easiest, quickest, and most effective mod there is (with the possible exception of maximizing your tire pressure).

- oh, and it didn't effect engine temp, at all, although it was pretty cold today -

You mentioned not wanting to shut off your engine for "only a minute or so". (!!!!) Some of us will shut it off for 10 to 20 SECONDS! I highly suggest you consider shutting off your engine if you're reasonably sure you'll be stopped for at least 30 seconds. Idling while not moving = zero MPG. That really skews your average DOWN!!!!!

[SilveradoMike]

You mentioned not wanting to shut off your engine for "only a minute or so". (!!!!) Some of us will shut it off for 10 to 20 SECONDS! I highly suggest you consider shutting off your engine if you're reasonably sure you'll be stopped for at least 30 seconds. Idling while not moving = zero MPG. That really skews your average DOWN!!!!! [/QUOTE]

The problem with this for me is I make an average of 60 deliverys a day each ranging in time from 90seconds to 10 minutes. I will usually shut down the engine if I know its going to be more then 2-3 minutes. Starters arent cheap and arent easy to replace on my truck.

[wmjinman]

Well, your choice, of course.

And you could be right (I often wonder what it will be like when the time comes my starter dies & I have to replace it. Will I wonder if it was all worthwhile at that point?)

One thing I've noticed though, is with the ScanGauge, I can see my average mileage for the tank drop while sitting at a stoplight idling. - really drives home the concept (at least it did for me)

Oh, I updated my "garage" with a picture of my other car (Suzuki Swift) with the duct tape grille block that saved me almost 2.5 MPG. Just click on "The White Gnat" in the column to the left to see it. Cost was a roll of duct tape and maybe 15 minutes to "install". - a pretty cheap & easy 2.5 MPG!!!

[Frank Lee]

On my Fords, at least, starter ills were caused by worn out brushes. So I pulled the starters, disassemble, clean, put new brushes in, lube it all nice with new high-tech synthetic lube, and presto! Good as new for under $20.

[SilveradoMike]

Its the issuses the starters in mine have. I usually have an extra one laying around thats all ready rebuilt. But that costs about 100 for the rebuild. And I usually already replace it twice a year.

[Frank Lee]

That sounds like an abnormal failure rate. Might need shims or ?

[SilveradoMike]

No theyre shimless. Bolts to straight to motor. I already start my truck 10-15 times a day.