LJRoy

here we go again...

I've tracked every single fill up since I drove it off the dealer lot. 84K miles, 164 fill ups, and the lifetime average is currently at 18.98mpg. That includes all towing - even the 5K trip I averaged 12mpg on. If I excluded the towing tanks I'm sure the average would be well over 20.

'03 HO/6 spd/4x4/SRW/3.73. all stock but do run Delvac1 in the engine and syn lubes in the diffs.

I will admit you guys with the new trucks are worrying me though with these reports of 12mpg empty. I've spent close to $9K in fuel already. If I had to re-drive those miles at 5-7MPG less and at current fuel prices - it would be closer to $20K.

triplenickle

When I first found out after I bought my truck that it didn't have the 325/600 motor, I felt jipped. But like LJRoy said- it does make me concerned about the mileage of the 04.5 and up. I hope it is just because they are so new- once they get loosened up, they'll get better. Now I'm glad as heck I've got the 305/555. More power than I can use in a hundred years, and very impressive mileage.

I wouldn't doubt for a second to hear someone talk of consistently 20+ in an early 3 gen.- as long as they dont say they pull 6 K @ 72 MPH and 2200 RPM.

trik396

Just checked this morning. Hand calculated. Filled to the neck thanks to vent mod. 366 miles and used exactly 22.1 gallons = 16.56mpg. This is with the overhead showing 20.1mpg. This is 50/50 city/highway driving and a few too many WOT sessions. And I'm talking Chicago city driving which blows...
On highway only at 60mph I've calc'd 20-21mpg on many occasions. Can't really complain about it...

Broncolou

I get 16-17 hand calculated empty mostly highway, and 9 towing 16k race trailer. All at speeds between 65-75.I watch my mileage all the time and hand calculate. I did slow down to 64 mph for one short towing trip and got about 11.

super_b ak

I average 18mpg on the highway if I keep it at 65. Seems like every 5mph faster over that is about 1 mpg less. I was averageing about 20mpg before I got the 35's, but they look to good to lose. Seems like I get 15 around town but I dont track that as close.

five20too

Does it help at all to put the tailgate down or use a tonneau cover? I've heard both ways and haven't ever tried it. I stay around 18mpg but would like to see the 20's that some are getting.

panheadindy

I hand calc every fillup since new. Just turned 8000 miles. My last 4 fillups have been
19.9 mpg
19.9
20.4
19.9
Every tank is topped off so I can see it in the filler pipe. My daily trip is 140 miles with 25-50 miles hwy (70mph). The rest of the trip is country roads where I average about 50mph. No real city driving or alot of stop and go to speak of.
I am very easy on the throttle and I think milage is a direct relation to weight of foot. I could easily see dropping down to 14 avg if I had a heavier foot. I gained an easy 3mpg leaving winter fuel. Off the dealer lot average was 14.5mpg. Overhead reads about 2mpg less then hand calc.
I traded an 04 Hemi 1500 for the diesel and am glad every second I did.

v8440

Lowering tailgate at best is a wash, and probably hurts. Tonneau covers are a definite help. Here, read this. It's long, but well worth it.


http://www.dodgeforum.com/m_447500/tm.htm

Stingerpup

Truck is as per sig. Mileage before reflash last year, averaging about 14-15 mpg per computer....14 hand calculated. After reflash, I am getting 16-17 per computer, closer to 16 hand calculated (75-85% highway mileage). If I am dragging/pulling my 20 ft V-nosed enclosed trailer @ about 7k lbs....10-12 mpg per computer and hand calculated. These MPG figures are based on a speed that maintains my RPM below 2k.

The tailgate up/tailgate down question was answered pretty well on Myth Busters. Took two identical new style F150s, drained the tanks, filled them up with exactly the same about of fuel. Then they took them out on the highway, locked in the cruise control and let 'em rip over the same course. The truck with the tailgate up got about 5 miles farther down the road before it ran out of gas.

They showed with fluid dynamics that the tailgate up creates a deadspace air pocket that allows the air to flow smoother over the truck, reducing drag.

WACTD

Tonneau cover definitely helps. I saw an immediately increase of 1.5-2.0 MPG after installing mine. Even my wife noticed the MPG increase.

cquestad

Unloaded - 16 mpg
Loaded and Towing - 13 mpg

BUT...that is at an average cruzin speed of 85 mph (or more )

RVT223

I get about 13-14 in town here in Denver...which stinks...and is why I ride my motorcycle when I can. On the highway between 18.2 and 20.2 empty. If I drive nice I get in the high 19's to low 20's. If I am in a hurry and making best possible speed my mileage dips down to low 18's high 17's, but that includes cruisng speeds above 85mph. Besides sometimes it fun to go more than 100mph...wish the tires were better able to handle high speeds for prolonged periods. By the way 05 2500 48RE...BDDL on perf.