Poor Mpg
New User
Joined: Apr 2008
Posts: 21
Likes: 0
yes
Other people have said that there 7.3 gets around 25 stock. I cant check the millage currently because the truck is off the road, And i know my dads math was not off he was a pilot so he had a thing for calculating millage and stuff. We did the same drive every Saturday morning and night exactly 46km or something for 8 years and we rarely filled up. Real shame my dad bought a new GMC with the 4 cylinder rice in her thinking it would get better millage now he wants the 7.3 back because his new girl only gets like 10mph
New User
Joined: Apr 2008
Posts: 21
Likes: 0
no
No im not, here in Canada most cars are measured is MPG but some are in KM per L. But you know what guys this is what i was told when i get in on the road in a few weeks i will do my own test
Lead Driver
Joined: Nov 2003
Posts: 6,900
Likes: 3
From: Campbell River, B.C.
Well actually the system thats supposed to be used up here is liters per 100 kilometer. One of the dumbest systems I ever saw.
What size of gallon are you using in your calculation? (3.87L or 4.00L gallons)
What size of gallon are you using in your calculation? (3.87L or 4.00L gallons)
Senior User
Joined: Jun 2004
Posts: 477
Likes: 1
From: florida
the mechanic who rebuilt my 7.3 has a 250 van with a 6.9. he says he gets over 20 all the time. its an automatic too. if i baby my 7.3 superduty and hold it at 60 mph, i can get 15. but loaded and pulling a trailer, my milage drops to 11-12 mpg. i have a ZF 5 and 355 gears and at 70, i'm turning 2200 rpm.
Senior User
Joined: Feb 2007
Posts: 191
Likes: 0
From: Denair, CA
It's an auxiliary transmission that acts much like a 2 speed rear axle. Basically gives me 2 different ratios per transmission gear (direct and under). I'd hoped it was an overdrive when I purchased the truck but it turned out to be an underdrive. I suppose it was probably an alternative to adding a turbo for pulling heavy loads. I have no problem getting off the line but it does nothing for fuel economy or top end.
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 16
From: Nutter Fort, WV
When you say cube van, are you talking about something like this?
fire7882, thanks for the picture.
With that much frontal area to get 30 MPG the top speed must have also been 30 MPH.
Even using Imperial gallons I can't see 30 MPG.
I bet the MPG was higher back in the early 90's when we still had high sulphur fuel, but with the ULSD of today, you will be lucky to get 16 MPG at modern speeds.
fire7882, thanks for the picture.
With that much frontal area to get 30 MPG the top speed must have also been 30 MPH.
Even using Imperial gallons I can't see 30 MPG.
I bet the MPG was higher back in the early 90's when we still had high sulphur fuel, but with the ULSD of today, you will be lucky to get 16 MPG at modern speeds.
Posting Guru
Joined: Oct 2006
Posts: 1,078
Likes: 2
From: New London, Mo
my 6.9 would get better mpg if it had an overdrive. i have a c6 with 3.73s or 4.10s. when i run it hard it gets better fuel milage then when i run it easy.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
More Turbo
Joined: Sep 2007
Posts: 552
Likes: 9
Well fellas with all the talk of mpg going on I might as well throw in my 2 cents. I just bought my first diesel a 91 f-350 after checking with you guys on a few details to watch for I bought it. it has the 7.3 idi we picked her up in ohio filled in ohio and drove the pa turnpike back to harrisburg logged 298 miles exactly we refilled in our hometown. check this out 298 miles used 14.2 gallons of fuel my son never even had to switch from the back tank! Im impressed this is a crew cab truck with a century cap on back. since im new the diesel scene is this just a fluke is it gonna fall through the floor hope not. I dont know my gears it does have overdrive and we were driving 68 mph steadily and my son said she was taching about 1900rpm. Im happy this old girl has 288,000 miles now. now i just need to figure a good maintenance schedule any body with any ideas here. I would like to keep this old girl going for another 288,000 thanks guys
Calculation 298 divided by 14.2=20.98 !!!
Calculation 298 divided by 14.2=20.98 !!!
Posting Guru
Joined: May 2003
Posts: 1,242
Likes: 3
From: Joliet, Illinois
And i know my dads math was not off he was a pilot so he had a thing for calculating millage and stuff. We did the same drive every Saturday morning and night exactly 46km or something for 8 years and we rarely filled up. Real shame my dad bought a new GMC with the 4 cylinder rice in her thinking it would get better millage now he wants the 7.3 back because his new girl only gets like 10mph
HMMM.
When one person says he averages 25 to 30 mpg when the rest of us get only 15, perhaps 20 if they try real hard, there is usually an issue with accuracy.
I get between 13 and 15, but I feel I might get 18 or 20 on a steady freeway cruise with no stop and go traffic.
Pull my big mirrors off and install a bed cover or one of those slick sloped camper shells and drive like there is no pissed off traffic piling up for miles behind me, and some tell me I might be able to get 22, perhaps even 25 MPG, but to get 30, I have to wonder if it would have to be all down hill miles!
Well, there is an interesting article at EVWORLD FEATURE: Free Fuel Riding on the Wind:KNOX | TOYOTA | TRUCK | AERODYNAMICS | STREAMLINE | EIFFEL | TEXAS | PHIL
Using the principles of aerodynamics, Phil Knox's recent additions of an aero-shell, under-belly pan, rear wheel skirts, wheel covers and grill block to his 1994 T-100 Toyota pickup improved his gas mileage by 28 percent over the original highway mileage.
So going from 15 to 30 is a 100% increase.
With all the Aero mods made, they only got a 28% improvement, and he made no mention of Aero modifications, and as far as his truck getting 30 mpg?
I wish I could get the sound bite from DR EVIL with this post saying, YEAH, RIGHT real slow and skeptical.
Postmaster
Joined: Mar 2008
Posts: 3,255
Likes: 0
From: Sweet Home, OR
There was an article in "Diesel Power" about a Dodge getting 30 mpg. They had to go to the extremes of removing the rearview mirros and blocking off the radiator completely etc., with a 2wd truck!
I won't call the 30 mpg guys liars but........
I won't call the 30 mpg guys liars but........
Lead Driver
Joined: Nov 2003
Posts: 6,900
Likes: 3
From: Campbell River, B.C.
Our trucks aren't really built for MPGs, but aero modding does go a long way. My guess is that a bellypan should be worth at least 3 MPG. The large side mirrors are like air brakes in jet fighters. I know my boxy cab height canopy does nothing for MPGs
I used to get 16 MPG consistently and I don't baby my truck on the freeway, but have started towing consistently since the E4OD swap. MPG seems to have stayed unchanged thanks to the locking TC (not a heavy trailer).
I used to get 16 MPG consistently and I don't baby my truck on the freeway, but have started towing consistently since the E4OD swap. MPG seems to have stayed unchanged thanks to the locking TC (not a heavy trailer).
Thread
Thread Starter
Forum
Replies
Last Post
Gold Dog
Big Block V8 - 385 Series (6.1/370, 7.0/429, 7.5/460)
5
Apr 24, 2008 12:24 PM
knolltkford
1999 - 2003 7.3L Power Stroke Diesel
4
Mar 24, 2007 10:49 PM
