Ford 7.3 chipped mileage

[Twain]

I have a '99 F-350 dually, 4.10 rear, 4x2, that 3 years old to us. It has a Diablo sports chip in it that is not self programmable. Owner said it was tuned for towing and the chip is so old that Diablo can't tell me anything about it. I get 16 mpg unloaded on the highway and about 12 loaded/towing 7,000 lbs TT. I've seen people claim 23 mpg highway and 17 towing with the same truck, but with different tuners. Can this truck really get much better mileage with a different chip or are people using special math?

[blderman]

majorgator wrote:
I have a '96 F350 7.3L 4x4 SRW Crew Cab Long Bed with E4OD and 4:10 rear end. It has lots of mods: 5" exhaust, Tymar Intake, Stage 1 Injectors, Tony Wildman 6-Pos Chip (plus many, many other mods for towing and aesthetics). When the chip is in the "economy" position, its supposed to get the best mileage. When in the "daily" position, which is where I run most of the time, it gets about 16 MPG unloaded. When towing (and in the "towing" setting), I get about 10-12 MPG depending on what I'm towing. I don't tow more than 60 to 65 MPH for fuel consumption purposes.

To the OP, the mileage numbers you're referencing are possible with smaller injectors, big intake, and big exhaust, chipped computer, smaller footprint truck, 2WD, 3:73 gears, and without getting into pedal too much. I've read people on the truck forums claim over 20 MPG under these circumstances when not towing, but even the 17 MPG while towing a heavy load seems optimistic. Unfortunately, its not fun to drive these trucks like this. Mine is a fast, fast truck, especially between 25 and 65 MPH...but I pay for that with poorer mileage.

blderman wrote:

...This is coming from someone who has spent $5,000+ trying to make my 7.3 perform like my stock 05 Cummins; as you can see from my signature, I still miss my Cummins.

Its a common problem...going from 6 cylinders to 8 cylinders. I hope that you come around to the all that the 7.3L has to offer LOL 😛

I've had the 7.3 for 5yrs now and still don't like it. It's actually going up for sale this week and I will be going back to a Ram.

[Tlauden]

I know a lot of people with chipped 7.3's. Most claim low 20's on the highway ( non-towing). It seems that the TS 6 position chip is the popular one around here.

[OH48Lt]

My neighbor has a stock 99 F250 extended cab 7.3 4.10 rear and the manual tranny. We've discussed this several times since I used to have a 2005 F250 6.0, and he says he can easily get 20-22 mpg on open road, hand calculated. I'm thinking that manual trans helps a bit on the highway road, as there is no torque converter slip with that. No idea what he gets towing anything.

[Rockrash]

All of my numbers are hand calculated. I can show every gallon of fuel that I have put it into my truck since the day I bought it.

[crcr]

It would be helpful in this thread (and all threads, for that matter) if those quoting fuel mileage would state whether they are quoting numbers from the onboard computer, or actual hand calculated numbers, fill up to fill up.

Personally, I have no interest in anything other than hand-calculated numbers. There is a reason that the MPG read out on vehicles is often called the lie-o-meter.

[Rockrash]

NRALIFR wrote:
Then you're not getting 30+ MPG. It would be more honest and accurate to say that your cost per mile or per gallon is X. It will still be an impressive number to the rest of us who know what a gallon of Diesel costs.

Just FYI: waste veggie oil (WVO) has just slightly less btu's per gallon compared to Diesel. WVO is about 120,000 btu/gal and Diesel is about 128,000-130,000 btu/gal. So with a 50/50 mix I would expect to see just slightly lower total MPG vs. 100% Diesel if you were measuring the fuel quantity accurately enough.

You've given me a great idea though. Everyone knows the 2008-2010 6.4 PSD's get awful fuel mileage in stock trim. From now on though, I'm going to start stating my MPG based on just the amount of Motorcraft Diesel additive I add at each fill-up, which is about 6-8 ounces. That should get me some impressive numbers!!! :B

:):)

That's the advantage of the old 7.3, no mod needed. I really don't see a drop in mileage compared to running straight diesel, but I drive like I'm 85 and the straight drive also helps. I'm sure my pulling numbers will drop.

[Turtle_n_Peeps]

Rockrash wrote:

majorgator wrote:

Rockrash wrote:


Long bed, 2wd ex cab 6spd. The secret is veggie oil. I get used oil from local choke-n-puke, filter, mix, drive.

Are you basing your MPG numbers on actual fuel level (oil plus diesel) or just the amount of diesel you're using? In other words, you're only using the total number of gallons of diesel added to the mix in order to determine the MPG...??

Correct. That is my mpg on diesel. I'm still getting 20 total, but my cost is less than $.10 per gal of veggie oil.

You really consider a career with the government! That's the way they do math and figure things! :B

[NRALIFR]

Then you're not getting 30+ MPG. It would be more honest and accurate to say that your cost per mile or per gallon is X. It will still be an impressive number to the rest of us who know what a gallon of Diesel costs.

Just FYI: waste veggie oil (WVO) has just slightly less btu's per gallon compared to Diesel. WVO is about 120,000 btu/gal and Diesel is about 128,000-130,000 btu/gal. So with a 50/50 mix I would expect to see just slightly lower total MPG vs. 100% Diesel if you were measuring the fuel quantity accurately enough.

You've given me a great idea though. Everyone knows the 2008-2010 6.4 PSD's get awful fuel mileage in stock trim. From now on though, I'm going to start stating my MPG based on just the amount of Motorcraft Diesel additive I add at each fill-up, which is about 6-8 ounces. That should get me some impressive numbers!!! :B

:):)

[Rockrash]

majorgator wrote:

Rockrash wrote:


Long bed, 2wd ex cab 6spd. The secret is veggie oil. I get used oil from local choke-n-puke, filter, mix, drive.

Are you basing your MPG numbers on actual fuel level (oil plus diesel) or just the amount of diesel you're using? In other words, you're only using the total number of gallons of diesel added to the mix in order to determine the MPG...??

Correct. That is my mpg on diesel. I'm still getting 20 total, but my cost is less than $.10 per gal of veggie oil.

[majorgator]

Rockrash wrote:


Long bed, 2wd ex cab 6spd. The secret is veggie oil. I get used oil from local choke-n-puke, filter, mix, drive.

Are you basing your MPG numbers on actual fuel level (oil plus diesel) or just the amount of diesel you're using? In other words, you're only using the total number of gallons of diesel added to the mix in order to determine the MPG...??

[Rockrash]

majorgator wrote:

Rockrash wrote:
My 250 7.3 6spd gets 20 mpg unloaded consistently on paper. 14 mpg towing. I recently started using additive mixing 50\50 and now get 30+mpg on diesel empty, haven't towed with it yet. I know, you say I'm full of poo with those numbers, but I can prove it any day of the week.

Do tell...how in the heck are you accomplishing that? I'll reserve my full level of doubt until I hear from you. What's your gear ratio? Are you running dyed fuel or ULSD? 2WD or 4WD? Crew cab, standard cab, short bed, long bed...???

Long bed, 2wd ex cab 6spd. The secret is veggie oil. I get used oil from local choke-n-puke, filter, mix, drive.

[cummins2014]

majorgator wrote:

Rockrash wrote:
My 250 7.3 6spd gets 20 mpg unloaded consistently on paper. 14 mpg towing. I recently started using additive mixing 50\50 and now get 30+mpg on diesel empty, haven't towed with it yet. I know, you say I'm full of poo with those numbers, but I can prove it any day of the week.

Do tell...how in the heck are you accomplishing that? I'll reserve my full level of doubt until I hear from you. What's your gear ratio? Are you running dyed fuel or ULSD? 2WD or 4WD? Crew cab, standard cab, short bed, long bed...???

Well you read it on the internet so its got to be true, but that post is tough to believe. Never have I read about a 7.3 getting that mileage, and I used to hang out on ford diesel forums a lot, and have read many many mileage threads . Must be a special calculator being used there 🙂

[majorgator]

Rockrash wrote:
My 250 7.3 6spd gets 20 mpg unloaded consistently on paper. 14 mpg towing. I recently started using additive mixing 50\50 and now get 30+mpg on diesel empty, haven't towed with it yet. I know, you say I'm full of poo with those numbers, but I can prove it any day of the week.

Do tell...how in the heck are you accomplishing that? I'll reserve my full level of doubt until I hear from you. What's your gear ratio? Are you running dyed fuel or ULSD? 2WD or 4WD? Crew cab, standard cab, short bed, long bed...???

[Rockrash]

My 250 7.3 6spd gets 20 mpg unloaded consistently on paper. 14 mpg towing. I recently started using additive mixing 50\50 and now get 30+mpg on diesel empty, haven't towed with it yet. I know, you say I'm full of poo with those numbers, but I can prove it any day of the week.

[majorgator]

I have a '96 F350 7.3L 4x4 SRW Crew Cab Long Bed with E4OD and 4:10 rear end. It has lots of mods: 5" exhaust, Tymar Intake, Stage 1 Injectors, Tony Wildman 6-Pos Chip (plus many, many other mods for towing and aesthetics). When the chip is in the "economy" position, its supposed to get the best mileage. When in the "daily" position, which is where I run most of the time, it gets about 16 MPG unloaded. When towing (and in the "towing" setting), I get about 10-12 MPG depending on what I'm towing. I don't tow more than 60 to 65 MPH for fuel consumption purposes.

To the OP, the mileage numbers you're referencing are possible with smaller injectors, big intake, and big exhaust, chipped computer, smaller footprint truck, 2WD, 3:73 gears, and without getting into pedal too much. I've read people on the truck forums claim over 20 MPG under these circumstances when not towing, but even the 17 MPG while towing a heavy load seems optimistic. Unfortunately, its not fun to drive these trucks like this. Mine is a fast, fast truck, especially between 25 and 65 MPH...but I pay for that with poorer mileage.

blderman wrote:

...This is coming from someone who has spent $5,000+ trying to make my 7.3 perform like my stock 05 Cummins; as you can see from my signature, I still miss my Cummins.

Its a common problem...going from 6 cylinders to 8 cylinders. I hope that you come around to the all that the 7.3L has to offer LOL 😛