There's starting to be a lot more talk of the 5.4's on here so thought I would throw something else out there. I see most people stating that they are getting anywhere from 10.5 to as high as 13.5 mpg in town. I am getting between 7-8 in town.
Now granted, I don't drive a lot during the week as my office is about 6 miles and it is litterally stop and go so I know that hurts. However, this is a huge difference in what other people are claiming. I'm just wondering if something is wrong with my truck?
Even on the road, I only get about 14 non-towing.
I have put 285's on it but that wouldn't make that much difference?
2003 F250 CC 4wd 5.4 3.73
Any idea's, thought's, etc.?
Thanks

 

I just changed from 235 to 285 and my MPG appears to have dropped from 10.5 to 8.5. Its got somthing to do with the wheels turning slower than the taco thinks it is, and messing up the oddometer. The BFG website has a calculation tool for working the numbers out.

 

I drove from Indiana to Florida and back and got 12mpg on every tank, don't think i'm going to get much better, this was at 75mph with a new air filter, clean MAF sensor, and the tail gate down, kinda sucks, but it is a truck. I got 7 mpg plowing snow the other night, not bad...

 

Two tanks on my new 05 F250 CC V10 w/18" tires - On the first tank with around town driving only I got a solid 9 mpg. On the second tank driving up the pass to ski plus some town driving I did 10 mpg.

Total miles on the truck are 331. I sure hope this gets a little better.

The V10 sure does have lots of power and is velvety smooth. But it sure is thirsty...

I would expect you'd do 2-3 mpg with the 5.4.

 

If your truck is older than about a '90 model, drving with the tailgate down MAY get you a slight increase in milage.
Some time in the late '80s The NASA wind tunnel became available to the auto manufacturers and they started testing trucks in it. Trucks manufactured since about '90 (depending on manufacturer) are designed to manintain a "bubble" of air in the bed so that the air flows over the cab, over the bubble and on... With the tailgate open, the bubble is destroyed and the air comes down behind the cab and creates a "suction", increasing drag.
Check it out, put an empty pop can in the front of the bed and drive down the highway with your tailgate closed, then open the tail gate and drive the same speed. Oooops! there goes the can.
Consumers Union did a test sometime around '93 or '95, testing pickups with tailgate open, closed, bed cover on, and with a shell installed. The difference in mileage was less than one MPG on all trucks tested with the highest MPG recorded on stock trucks (no cover or shell installed) with the tailgate closed.

 

has anyone done a real world actual milage check with tailgate open and closed.

 

Crownie1,

I was getting 14mpg city with the 235/85's. I recently put on 285/75's on 16X8 rims and lost 1mpg. I now get 13 mpg. Your mpg is VERY low though, and I would definitely look into it. Could be any number of things. Check the obvious things such as: air and oil filters; oil levels; tire pressure; dump some fuel injector cleaner in the gas tank. Also, check (and clean with electronic's cleaner if needed) the sensor in the air intake by the air filter. This affected the performance of my truck. Since the fuel injector cleaner and after cleaning the air flow sensor, no more knocks/pings and truck seems peppier.

I also had my computer re-set to the spec's of the 285 tires so my odometer/speedometer would be accurate ($65 @ Ford).

If none of this helps, I'd definitely consult either a Ford mechanic or a shop that is a certified Ford repair place. Your mileage (ie, the 7-8mpg city)sounds more like you're constantly towing a heavy trailer INTO a stiff wind... and uphill both ways at that!

Best,
DS

 

Are you calculating mileage the old fashion way or just watching the trucks computer????? The computer could be off? I have a 2000 F250 cc 4x4 with the 5.4 3.73 and I get 13-14 highway 12ish around town and 8-10 towing.

 

--has anyone done a real world actual milage check with tailgate open and closed.

i check mine with every tank of gas, and the worst ive ever gotten driving unloaded is 15.0 mpg. usually averages around 15.3 mpg. drove 285 miles round trip a week ago with the tailgate down and got 15.5 mpg. and that was running 70 mph for about 90% of the trip, and driving through asheville for about 10%. so i would say its about the same for mine with the gate up or down. worst ive gotten towing 6-8k is 13.5 mpg. i always have the bed up when towing because the tailgate would hit the jack otherwise. just being light on the pedal will help quite a bit with mileage. my wife gets 10 mpg less than me driving her car because she holds it to the floor every time she pulls out or passes someone. already rebuilt the engine and tranny in a 99 model...

 

I'd have to see the 15 mpg and better if the truck you're talking about is the one in your profile... Are you going across the flat desert at 55 mph with a backwind? Worst towing at 13.5 with a 5.4? You have a factory anomaly if that's the case. Don't ever sell it. Either that or you're using some seriously fuzzy math. Your getting the mpg of a diesel when you're towing. Highly unlikely.

 

Hi, Crownie1. I see posts all the time on mileage and one thing that is very important when everybody jumps in is for them to list whether their truck is 2wd or 4wd. I constantly see people with 4wd comparing thier mileage to 2wd and they will always be SEVERAL MPG lower. No way around that.

The tailgate open or tonneau cover, etc. creating better milage is a myth. I have tested this theory myself and have found no measurable difference.

The easiest way to increase milage is to change driving habits. I drive the diesel and have to keep the rpm's to 2000 or less or the mileage drops off to nothing. Also, check the tire pressure often if you live in a cold weather climate. I live in Denver and the temperature can be in the 50s for several days and around 0 the next several days. This effects your tire pressure if you aren't driving long enough to fully warm up your tires and negatively effects mileage.

The next thing is to maintain your vehicle. Not just the obvious, but the less obvious also. I recently had a brake caliper slider freeze on me and my right rear brake was always applyed. I had noticed my mileage dropped, but I could not figure it out, not until the brake wore out. I fixed the brakes and the milage improved - almost two mpg. So, bad brakes, transmission, differentials, etc, can effect milage if needing repair.

The larger tires do not hurt your milage, but they do hurt your math. The circumference (distance around the outside circle of the tire) of the larger tires is greater than the smaller tires, therefore with each rotation of the tire, you have actually gone farther than with the smaller tires. So, when your speedometer says you are going 55 mph, you are probably going around 60 mph. The faster you go, the greater the spread - 80 mph is closer to 90 mph. So -- WATCH OUT FOR TICKETS! This also means that at 55 mph, you are shorting yourself 5 miles every 55 on your gas mileage calculation. That hurts. So, go get your speedometer calibrated, or check into a chip or programer that corrects the speedometer (I know the diablo Predator will do this on the diesel).

Hope that helps.

 

I agree about the only way to get that good of mileage (15 mpg) with the 5.4 is with a 2 wheel drive. If it is a 4x4 than it is a rarity!

 

8 mpg no matter what I do. empty or full plowing or not. go figure I'm happy its a work beast.

 

That's definitely the other end of the spectrum... With hills, 12 1/2" wide tires and my leg in it, I get 11 usually. I'd check that out. Somethin skwuwy goin' on wound heah...
The guy with 15 mpg has a 4x4 according to his profile...

 

5.4 4x4 regular cab 6700 miles on the odo 15.3 on the last full tank. the last tank was around town with no extended expressway travel. during the holiday season we pulled a parade float a little over 2800 miles and the truck averaged 11.2. the interesting part was that the mpg changed very little during the mountain driving which included the mtns of western nc and sw virginia area. it varied less than a half mile per gallon from the mountains to the flat lands of eastern nc and most of sc. i haven't any expressway numbers of late.