Hey all, what's kind of milage should I be getting out of this beast?

1992 F-350 Crew Cab
7.3L Auto 2WD

I'm currently getting 11MPG, but my TPS is messed up so I hope to improve on that by replacing it.
Also, how do you access the codes in this truck? Can it be done without a code reader?
TIA.
-Niles

 

Welcome to FTE. My 90 gets about 14-16. Depends what you haul and how you drive. Also depends on your rear ratio. You can go to Auto Zone and they will read the codes for you I think. You can test the TPS with a meter. Do a search and you will find info on milage and also on the TPS.

 

90 250 4x4 s/c 3.55 zf5 18 mpg solo 12 towing 9000+

 

Thanks for the replies, it sounds like I should be getting better than I am no matter what. I'm getting 8 when I'm hauling a loaded car trailer. The 11 is with no load. I replaced the TPS yesterday and that took care of the erratic shifting so hopefully that will help. Also, my air intake hose is missing so I have that on order at Ford. Don't know if that will help or not, but I'm going to get this truck back up to specs and get the best I can out of it.

 

16 @65 w/ 3.55's and 35" tires and a ZF 5spd.

tire size matter just as much as rear end gearing...

Good luck with the TPS thingy...

 

it depends on a lot of things. gearing is very important, because the slower the engine turns, the better the milage. the main thing is how it is driven. if you keep your foot in it trying to gain more speed the more fuel you will use. easy on the pedal and you will go as fast and fuel will improve greatly. my truck is supposed to be 170 hp, but thats at 3000 rpm. i run it at 2200, i don't know the hp, but i'm sure its not much. i'm currently driving from florida to new mexico pulling a small trailer. my wife is driving a lincoln navigator pulling a larger trailer. she is getting at least 20% better milage than i am. however i just added a compact tractor that weighs 2000 lbs to the bed of my truck. the additional weight did not seem to make any difference. i think i'm getting about 10 mpg loaded.

 

I haven't checked on my gear ratio yet, my tires are stock, 235/85-16
The TPS should make a difference, I was running about 2,600RPM @ 70MPH most of the time because it wouldn't stay in fourth gear most of the time. Now that it is I'm running @ 2,200RPM.
When I bought this truck a couple of months ago the engine would die when coming off the freeway, when tinkering around I found the fuel filter/water separator was literally full of water. It was better after draining it and shortly after I replaced it, the filter was badly rusted out on the inside. Someone was getting some really bad fuel. No more problems after putting the new filter on and I've run some good injector cleaner through the last few tankfulls. It runs great, so no apparent damage done.
Just got to get it to stop sucking fuel, $80 a fill up and only going a little over 300 miles doesn't cut it.

 

2200 @ 70 MPH in OD is 4.10 gears
2600 @ 70 in direct is 3.55 gears

An A4OD is direct in third gear.
The two RPM readings you give do not work out right.

 

Hmmm, don't know what to tell you, that's what it shows.
I'll try to find the axle code tomorrow when there's some daylight.

 

As an afterthought, isn't my tranny an E4OD?

 

Yes, that was just a typo...

 

The speed you drive/rpm you turn seems to make a huge difference. Below is my findings.

I have a 94 F250 4x4 super cab long bed with a IDI TD, E40D, 4.10 gears 235/85/16 tires at 80psi. The truck had 122k miles at the start of the trip and a bit over 123k at the end. I drove it back from FL and tested the mileage. Here is what I got...the truck was basically empty...one motorcycle in the bed and pulling a jet ski on a trailer.

Cruise Control set at 70mph (about 2250rpm) --> 13mpg

Cruise Control set at 60mph (about 2000rpm) --> 16.5mpg

Cruise Control set at 55mph (about 1800rpm) --> 21.3mpg

All of the above figures are indicated (as opposed to GPS confirmed etc) and were obtained in very similar moderately hilly conditions on the same day and were tested for more than 100 miles.

 

Just a little update, changing the TPS and installing the intake hose helped quite a bit, I'm now getting 13mpg @ 70MPH and the erratic shifting is gone.
Still haven't looked at my gear ratio yet.

 

Converter slip if no lockup from O.D. not funtioning?????? I've seen them slip 300-400 rpm if the rpm is low enough and the load is high enough.

 

I have the same combo that you have, 92 f-350 crew cab, e4od, 4.10 but mine is a dually with a heavy utility bed. Best mileage so far is 16 (15.7) I started out at 10mpg just as you, and with some cheap mods, I have gained almost 6mpg. Here is what I have done.

1. Scanned for codes, found code for FIPL(fuel injection pressure lever) or what you are reffering to as the TPS. I replaced with new, and reset to specs with multimeter.

2. Remove the stock intake and toss it or burn it, etc. Remove the air cleaner lid, and cut out the soup bowl, so you have just the top cap left. Get a piece of 4" aluminum dryer duct hose, and route it down under the drivers side battery. and cut a tad out of the rad support to feed it through. I didnt have much room for a flange, so i just zip tied it in place

3. Cut off stock muffler, and replace with a see through for better flow. I left the stock pipe from front to rear, just replaced the muffler. a little louder but not much.

4. advanced timing to 7.5 deg

5. keep your foot out of it. I run at most 65 mph, but moreso around 60. take off from starts easly, etc.

I took a truck that i hated to drive, and now enjoy to drive, and it weighs more than most peoples f-350. Remember air in....exhaust out. once you get those two mastered, you can get more mpg.