I was only getting 13-14MPG on the tank after a 3,000 Mile Journey with a full 6x12 U-Haul in tow from Texas to North Dakota. MPH were on average 75-80 so I wasn't too surprised. I've noticed once you start getting over 2,000 RPMs on mine the MPG dumps pretty quickly.

Currently down a daily driver to and from work so I have been using the X to drive 100 miles a day. In this time I am using it I figured I'd start trying to figure out the sweet spot on the beast till I hunt down a VW TDI.

After 5 Tanks of driving back and forth to work this is what I found to get me the best MPG on my 2000 7.3L 4x4 X with 130K on it. Averaging 18.8-19.7 MPGs with the setup below via hand calculations. Lie-O-Meter is saying 23. Getting better MPGs on the chip set to "Daily" vs. "Economy" setting on the Beans Chip.

What are you guys getting on your Excursions? Also need to change the oil wondering what you guys are running?

MPH= 65-67 via GPS
RPM= 1800-1925
Engine Oil Temp= 203-205
Load %= 35-41
Tranny Temp= 115-130
Oil= Rotella 15w40
Additive= Half Quart Howes with 8oz 2-Stroke Oil per fill up
Chip Set=Daily (70+HP)

Stock Injectors & Stock Turbo

Engine Mods
4" AFE Intake
4" Diamond Eye Exhaust with Muffler Delete
Diesel Site 203* Thermostat
Sinister Diesel Coolant Filter
Beans Diesel Performance 6 Position Chip
Edge Insight Digital Gauge Monitor
New OEM Cam Position Sensor
Optima Yellow Top Batteries

Body Mods
4" Zone Lift
Hellwig Rear Sway
31" Nitto Trail Grapplers

Pending Install
Denso Starter
New EGP Tube & Sensor

 

I get the best mpg's at around 45 mph, If it's flat and you don't have to worry about the OD downshifting. Speed up before you get to the hills so you can crest them without loosing too much speed. That being said we drove 765 miles back from Yellowstone last week, I drove with the cruise set at 83 for best part of it

 

To achieve optimal fuel economy you **** to be going as slow as possible in the highest gear.

Is your ex really getting 19mpg? That's impressive.

 

Only getting 19 when I really baby it and cruise into the stop lights/signs. Changing out the EGP Tube and Sensor may have helped it out quite a bit. I cleaned it before but didn't get everything out so just replace the tube every 50K or so. MPG is taking a good hit when I hit cross winds or head on winds. Dropping 2-3 with strong winds.

Changing the oil out to 5W-40 Rotella was running 15W-40 for awhile when I was in Texas see if that makes any difference on MPG.

 

How long have you had the yellow top batteries in there?

Also why do you have a new starter waiting to go in?

 

9 months on the Yellow Tops, no complaints so far.

Still had the original starter, hasn't failed yet but wanted to get to it before it does. Just moved from Texas to North Dakota, wanted the tank ready for winter when it hits so upgraded batteries, Upgraded to the 1500 Watt Oil Heater, and wanted a higher torque starter. Also is the reason switching to 5W-40 vs. 15W-40. Should make it a little easier to start when it gets cold.

 

Keep it plugged in.

 

I would leave that original starter in there if it is working good yet. Can't beat that original quality, once you put aftermarket or rebuilt in you might be changing it every year.

 

2000 rpm for me. I think that's about 70 mph on the speedo. I have 235/85/16 on the rear with 3.73 gears. Waze says I'm 3-4 miles slower.