My '03 Excursion with the 6.0L PSD motor is working fine and all maintanence is current, however I am concerned about my constant low mileage of 14.6 - 15.0 on the overhead console for the past year or so.

Here is the status of my truck:

1) 131,000 miles on the truck.

2) Oil and filter changed every 5,000 miles with Rotella-Syn 5W-40.

3) Coolant changed flushed every 50,000 miles.

4) Tranny fluid & filter flushed every 30,000 miles.

5) Front and rear diff fluid changed at 80,000 miles.

6) Transfer case fluid has been changed and is current.

7) Tires are BFG's stock sized tires and inflated properly.

------------------------------

My mileage when new was 18 - 21mpg (before reflashing through the years.

My mixed driving is showing 14.6 - 15.0 mpg, but I feel this is low. If driving on the highway fulltime I get 16mpg - 17mpg if lucky?


Is there anything to look at regarding the front hubs or bearings? I am under the impression that they are factory sealed and never need being greased? I am concerned that somewhere on my truck is excess "drag" and "friction"??? When my brakes were replaced and my upper and lower ball joints replaced, no excess play or anything unusal was noticed.

Any ideas anyone... or am I being overly concerend and my mileage is "normal" for this motor?

Thanks,

Jeff

My 04 superduty shows 14 to 17 on the overhead with 315/70/16 cooper stt's. The wifes Ex shows between 16 to 20.5 on the overhead. Stock size BFG at's. So I agree that the milage is a little low.

Have you hand figured it?

Wasn't that about the time your area would have begun receiving ULSD instead of LSD? Just a thought.

Yes, we have had ULSD fuel for quite awhile.

Yes, I have suspected that for part of it, but since 2003, my mileage has gone down and with diesel at $3.79 - $3.89/gallon I hate filling it up.

Are the bearings factory sealed?

How will I know when they need replacing?

The front axle uses unit bearings which cannot be regreased. Gotta love Ford for those!

I get about 15 mpg on my 04. I had the front bearing service at 60K and they screw it up. with in the week had to replace the front bearing. at diff dealer.

Be concerned mostly with temperature readings that the pcm "sees". It uses oil temperature to make adjustments for warmup strategies, injector timing, turbo strategies, etc. If the pcm always thinks your truck is cold, it will always be attempting to get it to warm up.

Put a piece of tape over the mileage readout.

I think fuel definite cause of lower MPG. I have a stock '07 F350 SC, short bed, AT, 18" rims. I have tried to reconcile the difference in mileage between the 6.0L PSD and the Cummins or Duramax several sources report better MPG than the 6.0L. I have also tried to focus on the most cost effective ways to better the MPG in my truck. Last week I started using Powerservice "Diesel Clean". Rough preliminary data shows my fuel economy going from about 15 MPG city to about 16.5 with just that alone. I forget precisely what I paid for is at Walmart but it was something like $16 so I'll definitely get my money out of that. Next oil change I am going to try a synthetic oil (Mobil 1 5W-40 maybe?) from what I've read on that it is worth about 1 to 2 MPG plus extended drain interval out to 7500 m(I know that is what the manual says for normal oil changes I just would actually go that long instead of 5K). Other than that the only other item would be a programmer however I am not comfortable with this because my truck is under warranty and I would not want to compromise that at all. Not worth any argument even though I drive my truck responsibly and I get the idea that these engines are intentionally de-tuned for longevity/emission concerns. I know it is a full size truck but the others have no trouble producing the power at a higher efficiency. I wonder what changed over the years that the mileage dropped with the incremental flashes???

man did I kill this thread or what? Using Diesel Kleen for the first tank with city driving I hand calculated 16 MPG. Not bad! Diesel finally fell < $4/gal here in upstate NY.

Beach has been pretty much consistent with his usage of additives and quality fuel throughout the life of his excursion.

i'm assuming you didn't do anything obvious like a lift/tires

I use Diesel Kleen in every tank since new, or since maybe 10,000 miles.

Tires ate BFG All-Terrain KO's, but the same size as stock OEM "Rugged Trail model.

Truck is not lifted (stock).

I use Rotella-Syn 5W-40 as well.

Not much more I can do when driving the largest SUV made down the road. I actually call it the "bus" due to how many people I can carry and that it is shaped like a "bus or semi".

By the way, I do not suspect abnormal wear of the from bearings, even with 131,000 miles as my tires are all wearing perfectly and are rotated every 5,000 - 7,000 miles.

Thanks,