Thought some might be interested in this info as there are always lots of questions, especially to new expy buyers.
We just returned from a 5000 mile trip, northern Saskatchewan to California, Arizona and back. 2008 Expedition 3.31 gears. 7 people plus luggage tipped the scales at 7400 lbs. Lots of interstate, LA and Phoenix city, some highway. Averaged 18.2 US mpg (21.8 Cdn. mpg). Return trip averaged almost 20 (24 Cdn.) mpg but the first 2000 miles were TERRIBLE winds and roads and really killed mpg average.
We've been waiting for the ecoboost to come out for a new expy, but I'm reconsidering. I'm very happy with the 5.4 but would like a little more hp for towing. However, it's been very good (150,000 on it now), with only oil changes, 2 ball joints, brakes, and power window repairs. I love my ecoboost F150 and although the power is awesome, it won't touch the economy of this 5.4.
Out of curiosity, what gears do you have in your Ecoboost truck?
I have 3.73 gears because I ordered it with max tow package and that's what you get. I have 275/60/20 33" tires and the speedo is accurate. I can hardly bring myself to say it, but it has almost too much power. Not really, but definately more than I'll ever need. In retrospect I would order the highest gears and try to get more fuel economy, and still have plenty of power. My brother also has one with 3.31 gears and it's better with more than enough for towing.
I think I made a common mistake when ordering. I didn't account for the fact that the booster makes max torque at about 1800rpm while most make it at 4000+ (which really means they're not making much at 1800!). This truck runs about 1750 rpm at 65 mph. It's making max power right where it's running. Hardly notice the hills.
I'm just back from our ski trip to Colorado from East Texas. Started the trip with just 250 miles on her. She performed as expected. Mileage was 18 MPG average for 1950 miles. The Expy was quite, smoother, and the sound system were tons better than the old 2008 Tahoe. The only real gripe I have is the out of date instrument cluster. Oh well can have everything.
We also just got back from a Ski/ Snowboarding trip from DFW, TX to Show Low, AZ and back. (I am thoroughly impressed with the results.) trip legs that averaged 70+mph with up hill mountain driving =18mpg, when 65mph or less we got 20mpg.
(All calculations done by milage driven/ fuel consumed) not what the instrument cluster tells me I got... Although it was pretty close, with in .5-1mpg
Our 2006 Honda Pilot, which we sold to buy this one, only got 17mpg hwy. We bought our Navi last December with, 125K on it, mainly for this type of trip and others to follow.