2005 PSD Mileage issues

[UNRULEE]

I have a 2005 Ford F250 4dr, FX4, Lariat, and from the first day that i've owned (bought it in early '08) the mileage has never been that great. The most that I've ever seen on an all highway trip is 15.5, it's usually in the mid 14's. Around town is usually in the low 11's range. I don't drive with a heavy foot most of the time and try to keep the tach below 2k to better mileage.

Within the last year I've had a re-flash, had the egr valve and cooler replaced along with the oil cooler. I also switched to Rotella 5w40 syn and have started adding Powerservice at every tank full. All of this and I've never seen a change in MPG's? In fact it seems as of late that the mileage is getting worse.

I see a lot of people on the net can claim that their truck that is just like mine gets 13-14 in town and 16-18 on the highway (the original owner claimed that it got 12-13 on the highway pulling a loaded stock trailer, I've pulled my pop-up camper, which is at 4k lbs. max, and have seen 10-11.). I just don't see how.

Is this normal or is there a problem with my truck?

Thanks ahead of time.

 

[blacksnapon]

Remember, when people tell you their mileage, its seldom what they report. 15-16 isn't abnormal by any means. Close to 20 isn't the norm, its the exception.

 

[UNRULEE]

I'd be happy to see 15-16 on a normal basis, but that's only happened twice.

 

[bowtiehatr]

tire pressure and boost are what i hear most of. keep tires at proper pressure and no more than 10 psi of boost gets guys around here around 16 in town.

 

[UNRULEE]

Thanks for the reply 'hater. The tires are at the max psi, and I try to keep the boost a minimum.

Just made a 160 mile round trip with it. Left last night pulling an empty 5x10 small trailer, zero wind, half 65mph, half 75mph. Lie-o-meter (it's actually been very accurate the times that I've checked it) showed 10.8. Loaded up the trailer and the box this mourning (kind of heavy but no real load considering what I'm driving) and headed back and once I reached my destinaton the meter showed 11.8 (better, but not great). Seems odd to me. The truck did better loaded. Hills both ways are pretty even. This is all mostly on cruise control and in ND, it's not like we have anything even remotely resembling mountains.