Okay heres the scoop.

93 F350 4X4 7.3 nonturbo w/ e40d, 3.55's and 33" firestones. 247XXX miles
My only concern is getting good mileage.
So far I have removed the soup bowl and added a 3.5" exhaust. The exhaust comes from the manifolds and into a y pipe, thus eliminating all the exhaust being pushed through a single 2.5 " pipe. There is no muffler.

I am intrested in getting more mileage out of her, I have a little money to spend and a little time also. This is what I was planning on doing...

1. Changing front and rear axle fluids to synthetic
2. Adding a "forced air intake", similar to the ones seen on this website, w/ the exception that I intend to insulate the intake as much as possible trying to lower the intake air temperature, getting it as close to the ambient temperature as posibile.
3. Changing my air cleaner, right now it is a fram, Im not sure what filter to use, is the Purolater the best to use?
4. Removing the stock clutch fan and adding dual electrics with a variable temp setting sensor, most of my miles are on the open road, I do not need the engine to be turning that big old clutch fan all the time for no reason.

is there anything else I can do to help w/ mileage? Are there any adjusments that can be made with the IP to get better mileage? any and all suggestions would be gratlly apreciated.

By the way, right now I avg. 16-17 Mpg. I kow that this is good, but I also want to do better.

thanks in advance for any help and suggestions.

 

Skinny, high pressure tires would certainly help. Ideal would probably be 245/70/19.5 as you would retain about the same tire diamater, but would loose some width, gain pressure and load rating. If you go with a rib type you should loose some rolling resistance due to tread design too. If you want to retain the stock wheels, 255/85/16's might be worth considering when the tires are due for chainging.

Might also consider headers - I remember someone posting that with basically the mods you listed + headers they were getting 24mpg with easy highway driving.

Of course driving at a slower speed and accelerating slower will improve mileage as well. Though they can't hurt, I'd be really surprised if synthetic axle fluid gave any improvement in mileage. The front certainly will not as the front axle doesn't turn unless you lock the hubs in (or at least that's how it works on my 94').

Nothing you can do to the IP to get better mileage provided its properly timed and in good working order. Fresh injectors might help if yours are older.

 

I'll tell you what worked good for me. I adjusted the governor screw on the backside of the Inj. pump in about 1/2 turn. It doesn't change the power output of the engine, but it brings the torque in lower in the rpm range. It won't accelerate quite as fast, but EGT's stay lower. This allows me to short-shift the 5 speed at lower than normal rpms w/o any hint of lugging (pulls like a tractor). I am not sure if this will help you with the E40D, but it might. I now get 18-20mpg running empty and 13-15mpg pulling my gooseneck (24' w/tractor).

The main reason I did this was for pulling my gooseneck, it put the torque down lower in the powerband and made my truck pull hills better. The mileage was an added bonus. Hope this helps.

Bowedup

 

where can a guy find a set of headers? how much of a pain is the install?

 

I think you are wasiting your time. If mileage is your only concern, get the rpm's down and drive nicer.

Put a pair of 3.07's in there, or even lower if you can find them. Then, drive it better. I get that mileage out of my cc dually (4.10 rear).

 

Bowedup2003:
What exactly does this "governor screw" look like? Are you talking about the fuel adjustment scew inside the side cover maybe?
What kind of mileage did you get before?

 

The screw I'm reffering to is on the backside of the injector pump, just above the cone where all the injector lines connect to the pump. Mine has an allen head screw with a set nut, my buddies 91 had a small headed bolt with a set nut. Depending on which way you turn it adjusts where in the rpm range the fuel comes in at (as close as I can tell).

I adjusted mine out 3/4 of a turn, it took away some of the torque at idle (had to give her alittle gas to take off w/clutch), but it made the truck accelerate through the gears like a 350 chevy. It was a very noticeable difference. I ran it this way for about two weeks and was averaging about 14mpg. I pull a trailer alot so I kinda missed the torque at idle (take off w/o giving it gas). So I turned the screw the 3/4 turn back to stock, then 1/2 a turn more in to see what happens. It didn't give my truck any more/less power, but it put it down lower in the powerband. For example, I can take off from a dead stop with my 24' gooseneck in tow loaded with our 60 hp tractor w/o having to give it any gas. It also makes for pulling loads much better, I can hold speed going up hills better now. But to make a long story short, it helped my fuel mileage because I have the 5 speed, I can make all my shifts early w/o any lugging, I normally hit OD at about 45mph. I am now averaging 18-20, depending on where I get fuel, running empty.

Just try playing with it, if you don't like how it runs you can always set it back.

Bowedup

 

Thanks for the info Bowedup . I could use a little more torque .The hills are eating my lunch pulling a load . I'll have to play with it and see what happens . I average 16 to 18 empty and 10 to 13 loaded on the Highway with my 4speed , not too shabby .

 

My 88 F350 Crew Cab 4x4 7.3 IDI non turbo is lucky to get 13 mpg. I have the c6 three speed, that hurts on the open road. I have been thinking of swapping for a e4od, but the darn c6 is such a good tranny, I hate to change it, but I am sure OD would give me 4-5 mpg improvement. I might try your governor adjustment for towing. The C6 will pull hills all day at 50-55, but no more if it is a long steep hill. It won't down shift until below 45 mph. If I run interstate at 65-70 the mileage drops to 9-10 mpg tops, just to high RPMs with the three speed for decent fuel economy.


PW

 

Before I did this I would have to drop into 4th pulling loner grades and then I could hold 53-58mph pulling my gooseneck w/ load. After doing this I can usually stay in 5th (OD) pulling the same load up the same hills, dropping down to about 62-65mph. On long grades she pulls great, but short, very steep climbs still require 4th about midway up. If any of yall have ever traveled Hwy.79 between Buffalo,Tx and Palestine, Tx then you know the kind of hills I am talking about!

On another note, with this mod and the propane flowing, I can almost always hold 70mph pulling my gooseneck up the hills (long grades, not the above mentioned road!) but my EGT's will get up into the 1100 deg. range with the propane flowing.

Bowedup

 

I'm thinking ram air induction , headers , dual 3" and propane in the near future .

 

If I were you I'd go with a GV overdrive rather than swap out for an E4OD...

 

[QUOTE=cgrandahl64] 4. Removing the stock clutch fan and adding dual electrics with a variable temp setting sensor, most of my miles are on the open road, I do not need the engine to be turning that big old clutch fan all the time for no reason.

That is the only thing on your list i wouldnt do,some have tried but i dont think they were succesfull.The fan will only kick in when needed,(and you will hear it)other than that its pretty much free wheeling.

 

I adjusted my governor screw in a 1/2 turn and it does seem to lug a lot less when shifting at 1500 rpm. When I did a 0-60 time it was about 2 seconds slower, once I get to 2500 rpms it loses all its *****. Before it would power right through 3K.

Bowedup: do you have a turbo? I have propane but its just for show and maybe 5-10 extra horses. I found with the timing advanced the propane really jumps up the power alot. Without timing advanced its barely noticeable w/ the 'pane on.
My pump had a trox bit screw, I tried a allen wrench but it just stripped the hole out on my buddies GM 6.5. (I tried it out on his pump first)

 

well i would bump the timing a little it will burn the fuel thats being injected more completely and therfore giving u more power which means less throttle to accelerate and pull the hills also running powerservice or other diesel conditioners that clean the fuel system will do wonders especilly if u havent yet if its the first time double dose it and change the filter after that run it when u want i go every oil change(i pulled the injectors and they look new 155000) and sometimes more when i feel i want a little jump in power also i put engine restore in the oil so that it would seal any leaks along the cyl wall again it seems to work good doesn't use oil and theres a difference a good synthtiec oil will help too as it will reduce friction i wouldn't worry about exhaust headers if u can find them wont help much w/ the bigger exhaust u already have as said electric fan wont help since this is clutched its not a big deal the gov screw i havent heard of and sounds interetsing i would probably turn it down since it will pull the low end better then really over all the biggest jump u could see is w/ a turbo also a shift kit or banks tans command woudl help too i think tho not entierly sure and maybe someone who has one can chime in on that lastly i would suggest a performance atf i have hurst hot shift in right now and have run b&m trick shift both are very good and really firm up and make the tranny responsive i have the e40d like u so it will do the same thing other then that idk what else i would do