5.4L V8 Gas, Supercab not 4 door, longbed, 4X4, AT 6 spd, AC, PB, PS, tow package, not a ton of other options. The dash display will display the ongoing avg fuel mileage. It has always been around 8 or 9, but I've only owned the truck a six weeks. Bought from a for $24k from a Chevy dealership that had closed/purged inventory in 2008 and changed over to all Honda/Kia. So I got a good price.

Truck looked pristine underneath, which made sense for 38k miles. Everything on the truck seems to work so far.

I've driven it on the freeway twice EMPTY for around 25 miles. When I was driving empty I tried to use CC as much as possible, and I had the Two/Haul switch off ( This eliminates Over Drive ? ) Mileage display showed 8.6mpg. I kinda ignored that since it ran well, and I didn't buy it for good mileage anyway, but I was curious. How the heck could this get much worse mileage than my '94 Chevy K2500 with a 5.7L ? (350 with throttle body)

Any way, we bought a 2000lb cabover and picked it up this weekend. It was about 55 miles away so on the way back LOADED I carefully measured the mileage. With the camper ON I did use Tow/Haul mode.

My method was to ZERO the Trip A with the tank absolutely FULL. Then drive home (2 hrs, never more than 65mph ). Then refuel tank to FULL. Then divide miles from Odometer Trip A display by Gals listed on receipt. My math showed 9.47mpg. Display showed 8.9mpg all the way home.

Kinda cool Ford came up with a truck design that actually gets better mileage when LOADED and with 5 gears instead of 6. Maybe there is a tiny hamster inside on a wheel ?

This truck has had 4 previous owners. Orig. owner was for 3 years, and there are maint records for that time period ( Mostly oil changes, except for a front brake rotor resurface ? ) After that, it went from dealer to dealer, and only 1 oil change shows on the carfax. It does have a clean title, but I wouldn't be surprised if it was totaled and very nicely rebuilt. I don't see the Ford logo stickers on some body / drivetrain parts. I doubt it was rebuilt in someone's back yard, its just too perfect. There really is no evidence of any serious wreck.

What should I do about this mileage issue ? Where do I get a shop manual ? Any pointers on maintenance ? I'm only using this truck for my RV towing a small ( 900lbs ) boat and hauling the cabover. I'll Probably put less than 8000 miles a year on it.

 

Welcome to the world of never passing a gas station.. I have a 04 ext cab 5.4 and i get 12.3.. thats using the fuely app at every fill up. If you have not done all the fluid changes I would take care of that.. Filters also.. I some times use an 18 ft dovetail trailer to haul things around and I average 11 mpg when doing so. the Best I have ever seen MPG wise is 18.. Tail wind from OK to KS.. 70 deg outside and calm air..

 

I have the same truck but 2010 model year. I have had my truck for about a month and the best MPG display so far was 12.6. I don't use my truck for any towing or hauling so not sure how much worse it would get. I was hoping for higher gas milage but I also have not done any highway driving. One thing that bothers me is I can't get the display to show only the mileage. It will show the trip as well as the total milage on the truck.

 

Do you have winter gas mix where you are? I have a similar truck, crew instead of super, and my mileage took a nose dive when they started using it here.

 

My 99 SD has no stickers on any of the sheet metal parts IE: fenders, hood ,doors, bed or tail gate.
It has never had any damage from a wreck, and has all original paint.
So your truck may not have been in an accident .

 

AB-Normal 5.4L bad mileage is what I'm getting. I had heard about all the complaints from people with the 5.4L engine and their "too high" expectations mileage wise...


But I'm saying I NEVER got better than around 9mpg UNLOADED/EMPTY with Tow/Haul DIS-engaged. Maybe its worth taking the truck in for a Dealership to look it over, eh ? I spent a couple hours today reading all through several different forums....And from all the postings I've read, this is what I gather would be normal:

Around 13-14 UNloaded hwy mileage. Easily down to 10mpg with the Cabover Camper loaded and on the hwy. Anyone disagree with this expectation ?
Anyone know if I'm using Tow/Haul correctly and what it does, exactly ?

I hope to God this truck can do better than 9mpg EMPTY ON THE HWY.

 

I think we do...But perhaps I can find a station and get around that variable, its worth a shot. I drive from Vancouver, WA to Salem, OR on a regular basis.

 

This is good news. It does have a sticker on the radiator / tranny cooler saying made in mexico. Are these trucks assembled in mexico ? I will say this, doing the oil change was a snap, there is a TON of room inside that engine bay, probably so they could fit the V10 in there...

 

First rule is never believe the lie o meter, the only way to know is to hand calculate it. Winter fuel and cold are always going to cost you a couple miles per gallon.

 

I think the fuel up there is worse than south of you.
I do hand calculating , and my v10 only gets hiway driven , but I am getting much better mileage , more like 12-14

 

Well, so far my only hand calculation was 9.47mpg versus 8.9 on the display. That was pretty much worst case scenario, loaded with a Cabover camper & with Tow/Haul engaged.

I'm going to do an UNloaded hwy run, and accurately hand calculate the mileage.

Do I need to reset the mpg display somehow ?

 

My '05 SD 5.4 gets around 6mpg., hauling my work trailer that's about 7,000 lbs..

I've owned about every Ford truck and engine combo produced since 1970. I've never gotten better than 17-18 mpg with the most efficient, non-work, vehicle. Most averaged 14-17, an E-350 w/460 V-8 got 10 mpg.

My current truck is an '05 SD 250, 5.4, and won't get 400 mi. on a full tank (38.5 gals.) empty. I didn't buy it for economy, just based on past experience. It is under powered for the towing capacity rating/payload. I'd love to have another big block truck engine that's gas. What the heck, straining the guts out of 331 cu. in. small block isn't efficient, no more/less than an easy running larger engine.

I know, I could have easily just picked up a diesel, but you'd think with all the experience that is in these trucks and their history, someone besides the end user would realize that a small block, low h.p., V-8, shouldn't even have been offered in a 9400 GVWR, + trailer rating, work truck.

I'd be thrilled with 12 mpg. But, even falling off a cliff, it won't get that. And I just had the PCM flashed, hoping some upgrade might make it a little better. Hard to say now, with the super cold air.

Dave

 

Hand calculate your mileage. On winter blend, rural/city/highway driving and with this real cold/snowy weather (and the hubs locked) I am seeing 12.5-13 MPG.

Also, Tow/Haul mode does not lock out overdrive. It changes the shift points below 60 MPH.

How many miles are on this truck? Are the tires stock? Is it lifted?

 

I have no advice but to "keep your foot out of it". Obviously that doesn't help.

Regarding whether the truck has been wrecked or not:

My coworker's father-in-law was in charge of a Ford body shop. They have completely rebuilt vehicles of all kinds, and in almost all cases, you would never know the vehicle was wrecked. In many cases, they are salvage title jobs. From what I know they have always disclosed the damage and repairs to the purchaser.

Good luck on the gas mileage!

 

Redford

Not sure whom you are replying to, but if it's me, here's what I know.

Rear axle is 4:10, tires are 285/70R/17, mi. are 106,000. Engine routinely runs 2500 to 3000 rpm's. It'll never go on a pleasure trip, so extended highway mileage won't happen either. Truck is well maintained. I'm the 2nd owner.

I have no idea whether a lift pkg. was installed or not. I know I won't spend the time/money for mod's of any kind. I do know that the tires are larger than stock, but that size was on there when I got the truck ( @ 85,500 mi.), and I just replaced them with the same size.

I guess it's a trade off. Of all the Ford trucks and HD vans I've owned, this is the first one that does absolutely everything I need it to do, just at a high cost for fuel.

Dave