2003 6.0 Poor Fuel Economy ????

[97350]

I just came back from a trip pulling an 8000# trailer with my stock 3.73 6.0 4x4 crewcab and was disappointed with the 7-8mpg.There was alot of hissing under load and I've read that theres an exhaust flex that can crack.Could this cause poor mileage?Also I want to install a turbo back system and am concerned with uncorking the whistle.Any suggestions as to which is the best?

Anybody got a good combo that I can use to maximize my fuel economy?

Thanks

[hazard]

if you have a hiss under load i would check to see if your intercooler boots are snugged up and dont have any holes in them, and check for exhaust leaks comming from the bellows section in the exhaust up pipes to the turbo, if the exhaust leak is bad enough, your loosing a considerable ammount of exhaust energy to make your turbo operate correctly and effieciently, this can cause poor fuel economy same with leaking intercooler boots. as for the exhaust get rid of the cat and the factory muffler, i myself went with the silverline 4" trubo back system because it was priced right... all depends on what you want to spend on it really but they all do the same thing, most systems come with a flow through muffler which should keep the whistle of the 03 to a bearable level, but i hated the muffler on my 06 so i put a muffler delete pipe in it and will never go back, personally i wish i had the 03 turbo so i had the famous whistle but thats just me. hope this helps, if you have any more questions just ask id be glad to help in any way i can, there will be more guys chime in on this too.

[Blitanicle99]

Well I don't know whats wrong with your truck but I can tell you what I get and what I pull.


I pull a 28Ft Halmark 3 axle trailer with full tools, winch, fridge, ac, cabinets, the works.

Inside is a 2750 lb Time Attack Evo 8 (They call it "fast" lol)

No idea on the weight of the trailer, its a big *** enclosed trailer.


With that behind my 2003 F250 Super Duty 6.0 FX4, basically stock with no cat or muffler I get about 10-12 mpg. This is going uphill toward West Virginia. I might add my air filter is dirty as balls.


3.73 gears, again no programmer or aftermarket stuff just no cat or muffler.

I could get 7-8 but I'd have my foot in it more, when you have a load drive the turbo, not the truck. It gets your mileage up higher. Use the spool to your advantage when you need to get on it, don't make it downshift and pour fuel in there.

It might you just have a heavy foot?

[Hardline]

Originally Posted by Blitanicle99

I might add my air filter is dirty as balls.

Hey I just got out of the shower. Balls not dirty.

[Blitanicle99]

Originally Posted by Hardline

Hey I just got out of the shower. Balls not dirty.

Did you do the peanut butter trick with your dog again?

[cartmanea]

Originally Posted by 97350

I just came back from a trip pulling an 8000# trailer with my stock 3.73 6.0 4x4 crewcab and was disappointed with the 7-8mpg.There was alot of hissing under load and I've read that theres an exhaust flex that can crack.Could this cause poor mileage?Also I want to install a turbo back system and am concerned with uncorking the whistle.Any suggestions as to which is the best?

Anybody got a good combo that I can use to maximize my fuel economy?

Thanks

Back to the original post...

What speed were you running and what was the terrain like? Hissing could be an exhaust leak (look for soot around all the exhaust piping), or it could be an intake leak. On an '03 its very possible you have some intercooler boots starting to crack and leak. I wouldn't suspect and intercooler boot leaking a little would cause that poor mileage though. How does the truck run otherwise? Does it miss when started cold (injector problems) or any other symptoms?

[CCSBD]

If your worried about uncorking the whistle we can trade turbos

[zspear1]

You might check the silicone boot that connects the turbo charger and after cooler line. I found one that was split right on the clamp and behind where you could not really see it unless you took it completely off. If you go to the ford house they have a bigger better boot that resists splitting.

[97350]

Originally Posted by cartmanea

Back to the original post...

What speed were you running and what was the terrain like? Hissing could be an exhaust leak (look for soot around all the exhaust piping), or it could be an intake leak. On an '03 its very possible you have some intercooler boots starting to crack and leak. I wouldn't suspect and intercooler boot leaking a little would cause that poor mileage though. How does the truck run otherwise? Does it miss when started cold (injector problems) or any other symptoms?

My maximum speed was around 105kmh(65mph),and there was a bit of a headwind.The truck normally runs and starts great but the moment I hooked on to this trailer the engine belched black whenever I accelerated.Only did it for a bit then the smoke was gone.I don't have a boost gauge so I don't even know how much I have.I was hoping for better mileage and am considering an AFE tb exhaust with an S&B filter. Anyone tried these before?

[cartmanea]

The black smoke could be your EGR valve gummed up and sticking open.