I have a f250 94 4x4 IDI Turbo with E4OD and 4:10 gears. The truck has 33x12.5x16.5 mud tires, front level kit, stock intake, ATS outlet with 3" exhaust, new injectors, glowplugs, clean airfilter.

The best milage I have seen in the 6 months I've owned it is 15 mpg accelerating as slow as I can, and keeping to posted speed limits empty.

Cruzing at freeway speeds empty I'm closer to 13 consistently. This drops to 12 mpg if I cruise at 75 mph.

The terrain and how far I step into the throttle seem to have a huge impact on my fuel economy, which makes sense. Dragging 3.5 tons up a hill has to take more energy than traveling on flat ground.

 

the mileage is right inline with my 89 crewcab e4od and 4:10 gears
and the mileage didnt change at all after replacing the injector pump , then the injectors
and trying different timing numbers
the only real help would be if you changed the diff to 3:54 or 3:73

 

sorry i couldnt get back to you sooner been kinda busy. Im not sure if the injectors have ever been changed but the return lines have been. I have a brand new air cleaner. I get a whole lot of smoke under hard acceleration but the pump has never been cut up. The truck dont rattle like the timings off but it has had what i think is a rod knock for 170 thousand of the 180 thousand miles.

 

hi there i have a 7.3L IDI stock and i get around 30 mpg people keep saying this is great for the 7.3 but i donno. It is in a 1990 auto cube van if that has anything to do with is im not sure what gearing it has in it.

 

30 mpg????

Jason

 

Typo perhaps?

 

Or really bad math!

 

I'm just filled up today 257 miles / 17.2 gallons = 14.9 mpg. This tank full was about 50/50 towing my Jeep and commuting in Seattle traffic (my commute is about two thirds highway, and one third city streets - averaging about 35 mph for 20 miles both ways).

Haven't made any extended highway trips when I wasn't towing anything, but I'd expect somewhere in the 17-19 mpg range if & when I ever do. I have 4.10s and the ZF-5 with the .77 OD - pretty similar to your E4OD without the torque converter slippage. I have an old school Banks turbo to help out, but its also a dually 4x4, which offsets that a bit.

You should be getting better than 13 mpg unless it is all stop & go...

Is your speedo adjusted for those 33" tires? The stock size is 235/85/16 - which is about 31" diameter. Bumping up to 33" tires will make your speedo/odo read about 6.5% low - so you have to multiply your calculated mileage by 1.065 to get your correct mpg (13 x 1.065 = 13.8 and 14 x 1.065 = 14.9) so that puts you closer to the 14-15 mpg range...

 

don't sell than van, because your van gets the worlds best milage. lol just kidding. i once had a 1980 cadilac the got 30 mpg with a 5.7 liter diesel. my 7.3 ford truck loves diesel.

 

Before I started talking on this forum I thought 25-30 MPG was perfectly normal for this engine I just took it over from my dad who drove if for 6 years and would keep and calculate the millage of his vehicles, just to save a few bucks. It was driven 2 ways 1 hour one time a weed. Also any other person who has driven it has said the same thing. I am anything but an expert on diesel engines but I have had the hood up a few time and it sure is a massive 8V international diesel. I was only told it was a 7.3L IDI International. Is there something im missing it is a E-350 econolin, is it possible it has different V8 diesel in it or a modification we don't know about. I have been told that to get it up hill your food would always be right to the floor with a significant speed loss if that helps..?

 

I hooked up and pulled my trailer out from beside the house tonight and I think I burned a 1/4 tank going 50 ft . Man, I gotta change those injectors.

Jason

 

Yep, something like that as far as I can see, but on a ford full size truck.

And, what, to get 30 MPG out of a vehicle with that huge frontal area and weighs that much, it has to burn so little fuel like it has something in the range of 30 to 50 hp diesel going something like 30 mph max, if it could go that fast that is!

DUDE! your math has to be off BIG TIME!
Top off one fuel tank and only use that tank, zero out the odometer, drive it to almost empty (1/4 tank or so), top off the same fuel tank, record the miles driven since the last fuel up, and record the fuel used to top it off and divide the miles by the gallons.

I used to go a few tanks full before doing the math, then found that I forgot to record 1 fuel up and my fuel mileage skyrocketed!

 

You could still be driving a 5.8L gasser CrewCab like me getting 8.6 mpg. with a five speed no less.
Man I gotta find a 6.9.
I'm used to my Cummins, I'd get an honest 17 in mixed driving, I could claim more but it'd be a lie.
Crap! I just realised I'm only getting half the mileage I used to, dang growing family has forced me out of my old std. cab.

Breech,
What does your dual range do? I assumed it would give you an overdrive. Is it an underdrive?

 

I get 13mpg no matter what I do, I try to drive like grandpa around town and keep it around 60 on the highway and I still get 13mpg. Maybe the speedo is not reading correctly on the cube van. If it truly is getting 30mpg you better retire that thing to the ford hall of fame.

 

As a citi boy that does on the road flat land driving
with a E350 6.9, yah I get mid 20s economy...
hiway driving. Of course I'm not running 70mph
nor do I have all the stuff on this vehicle to plow
the back 40... reasonable mpg is possible with
these vehicles if that is what you bought it for; or
equiped it for! :<)