I am happy with my mileage when you consider how large these trucks are. And again, it will get better when it warms up.

 

Hmmm... Let me take a stab here. Loads of ~5,000 lbs? You were driving at what altitude? Temperature? Winter diesel? What percent grade and lenth of the hills? Was it snowing? What were the road conditions? -compact snow and ice? Even though it's slick, there's actually a large amount of drag when driving on it. Were you in 4x4 for any of the route? Where the hubs locked for this winter jaunt, unlike when towing in the summer? Was there a head wind? Were you keeping your foot on the throttle just to make sure that buddy of yours with the Dodge/GM behind you couldn't keep up?

I think what I and others have pointed out is that there are many factors that can effect the calculated fuel consumption. Tomorrow you might just get 17mpg. Also, your distance calculations and fuel consumptions are listed in metric measurements. Yet you're noting "mileage". Sounds like you're doing the math from the Lie-O-Meter. If your actual numbers are KM per mile, then I think there's an issue. Because many of us are getting 14-15 miles per gallon towing more weight through the mountains. And most of us are quite happy with that.

Driving easy and empty with mixed city and rural road driving I'm getting over 500 miles to a tank. You say you're getting 540km. I would think you should getting nearly 800km to a tank. Your 540km is only 330 miles. Right now I've got 312 mile on this fillup. The fuel guage needle has just dropped below the half line. (and I must be a lucky one, my guage reads just about dead on.) For that more than 500 miles to a tank, I am running sometimes until the low level warning is displayed.

Either you have a heavy foot, or there's some information not good, or there just might be a fuel consumption problem. The only way to really compare is empty load and similar driving terrain. Towing and loaded, brings in too many factors. You could have a missaligned trailer axle, or a brake that hangs. So, if you're concerned about your mileage, drive easy for a couple of tanks and get a good average. Filling up at half tank four times, doing the math, gives you enough information for a good average baseline. I keep a log of everything I do to my truck, Including every fill up. And I compute the consumption/mileage right then. Over time there will be fluctuations, but I know what to expect from tank to tank, loaded unloaded, warm or cold. If numbers are out of the norm, hopefully I'll be able to recognise an issue and get it taken care of.

 

Well for what it's worth, I've been charting my mileage since day one...and it aint too pretty. It was looking pretty good untill the day the drone started(2738mi) in early Sept...from there on out mileage droped and power seemed less...last tank, 14.98 pure highway unloaded, throught the Appalations at a constant 70mph/2krpm...the one before that around town/highway...10.49... Currently 5500miles on her...

Well that didn't work...why cant I get a pic to upload?...I'll try the gallery...

 

I have an 05 250 PSD reg cab, long bed with 1500 miles. I have been getting about 12-13 mpg Hwy/city combined, pulling a trailer that weighs about 3100 pounds. The first fivehundred miles I got about 15 mpg unloaded.

 

Last fillup mostly around town driving, 10.2 hand calculated.

 

Truck has hubs but also the switch on the dash, not a lever on the floor. I thought the hubs were vacumn operated on these trucks.
I need to evaluate tire pressure. However I am extremely sad due to the fact I was getting 17-18 for the same driving with a Dodge Cummins regular cab 4X4 long box that had 90K on the clock.
I have never seen betterthan 15 but chocked it up to the motor being new and breaking in. My mileage has steadily gone down hill with more miles.

As for my fuel guage. Mine will read a half tank with 150 miles on it. If the odo is anywhere near 300 I am just above the big 'E'.

 

My 05 PSD FX4 CC F250 is getting 16.8 mpg (hand calculated; computer says 14.7) as of now in city driving! I must be one of the lucky ones so far!

 

Unless they changed on 05's, your hubs should have an "auto" and "lock" on the hub so you can manually lock the hubs and leave them that way. If they are on auto, they are vacuum operated. You should be able to reach behind the wheel and carefully turn the CV joint. If it moves without moving the wheel, it is unlocked. Or, get under the truck (engine off) and turn the front driveshaft by hand. It should rotate with a little effort if the hubs are unlocked and the transfer case in 2WD. If your hubs are locked and but show in "auto" and the switch on dash is in 2WD, turn the hubs to lock then back to auto. That should release them.

As far as the gas tank goes, if you are filling up until the pump clicks off, you aren't filling the tank because of the foam. Once the pump clicks off, let a few seconds go by and slowly trickle fuel in. I can add several more gallons into the tank after the pump clicks off. If I fill it up to the filler neck, I can go 130 to 150 miles (city/hwy) before the fuel gauge comes off the "F" marker.

 

Sorry to hear about your drone. The only time I hear that is when I've selected the wrong gear for the speed/terain. Easy to do with the 6spd. That's when I'm lugging things down. She's torquey, but she don't really like 5th gear down at 1000rpm.

If my diesel ever got 10mpg at any time, loaded or not, I'd have it in for diagnostics the same day.

Just in the driveway tonight. 389 miles on this fillup and the needle's not quite halfway between half and three quarters.

I'm pretty sure that I read somewhere here that the latest flash for an 04' fixed a problem with fuel guage accuracy...?

 

My V10 gets 13 in the city and 15 on the freeways. If I average under 70mph, I get 16 mpg. ( of course, i don't have a lead foot)

You guys suck!

 

Hey sbv45 I have question for you. I have an 03 f250 crew cap short box 4x4 with the latest flash (i think). I live in utah where it is about 30-40 degrees. I have been trying to figure out my mpg and cannot get any consistancy filling it up. I have been filling it up until I can see the fuel in the tube. This last tank I got 420 miles. When I went to fill it I had an 1/8 of a tank and I put 29 gallons in my 26 gallon tank. This doesn't make any sense to me. A friend of mine brought up a good point, he said the fuel is more dense when it is cold so you should be able to get more in the tank. This makes sense to me and if it is true then how can you realy get any consistancy? I think the only way you can accuratly calculate your mpg is if you fill it up the same way every time at the same temp. Maybe you could shed some light on this. I don't know, I might just be stupid this is my first diesel.

 

SBV45, I know he asked you, and I'm interested in your answer, but I gotta chime in.

Huh? To the best of my knowledge, you should have a 38 gallon diesel fuel cell. Do you have two smaller tanks? My 04' PSD has the single 38 gallon.

As for density of fuel, yes it changes with temperature, but that doesn't change the volume it displaces by more than a percent or few. Yes, fill up in the morning to the brim, then on a hot day it spills out the over flow/vent. That's with a temperature swing of maybe thirty degrees. I doubt you're going to notice at current Utah temperatures. And you're not going to lose three or four gallons by that happening. 3% of 30 gallons= ~a little over a quart. The tank internal dimmension is a displacement of volume converted from cubic feet to liquid gallons. Simple as that. Fill it with sand, water or fuel. It's still a static value of capacity be it 29 or 38 gallons. Fill it with water then freeze it. As the water freezes it'll expand, (leave an unopened full can of beer in the freezer and you'll know what I mean), You've got more cubic feet of solid ice than you put in as water, but the amount of liquid is still that initial value less the evaporation when you thaw it out. Does diesel change this much. It'd be tough to convince me.

In one of the tech sections of this forum there's a thread about modifying the fuel tank to remove a good portion of the vent tube. It's supposed to allow a gallon or two more in the tank, and some say there's less, (some say more), diesel foam when fueling. You might read up on it. If you're getting a lot of foam with filling, hence an inconsistent fill calculation, then you might also try a different filling station. Some nozzles are worse than others. The fast flow units at the truck stops may not be the best for us with lil'trucks.

 

I'll betcha $100 he has a short bed.

 

[QUOTE=Super Uke]I just came back from the mountains with my '04 F350 4X4 Crew Cab shortbox. I had two sleds on the deck and 1 sled on two place trailer. I figured out my mileage and it worked out to 15 mpg...I didn't think that was very good. My truck has 20,000 and I just had a service done (oil, fuel filter, etc). Is there a different flash I should ask the dealer about? If so is there a # I should ask for? This is in Alberta, Canada..I don't know if there is a difference between Canadian and US flashes.

Hey Super UKE, I got the same truck but mine is a 250 (same gearing, tranny, etc). It is winter in the NE and the average temp is 10-30. I get the same mileage, About 14 towing light, 3000lbs, 12 towing heavy, 8000+ and usually 16-18 without trailer.

I consider it great. My F150 with the 5.4 liter engine used to get 12 or 13 not towing anything. I got a friend who tows a horse trailer with a Dodge diesel 4x4, his mileage is similar, same with the Duramax guy I work with. Of course it all depends on speed and driving habits.

 

My 03 Shortbed holds 34 gal. I emptied the tank and refilled it when I harpooned it.

Mine gets 17 combined at 85 MPH