Gas mileage

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Frank Swygert

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I get an average of about 13.5 with mixed city/highway driving with my 2005 (4x4, 5.4L, four speed auto, 3.73 gears -- tow package). That will put it at 10-11 city, 14-15 highway. I only get that mileage because I hardly ever drive it over 65-68 mph though. Tests back in the late 70s showed that aerodynamic drag increases exponentially over about 65 mph. Most vehicles were pretty much bricks compared to today's, so you can probably up that a few mph, but big trucks with large frontal areas aren't going to do much better. Just rounding corners does help though. If you're running 70-75 or taking off hard and fast a lot gas mileage is going to drop significantly. Mine drops to 9-10 mpg when towing my 7000# camper. I'm right at the max recommended payload when packed up for towing. If I boondocked with it I'd be 200-300 pounds over the tow rating . As it is I don't carry water in the tank or a generator, just use campgrounds with power and water.
 

Eldelewis

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My 2004, 5.4, 3:73 geared, tow package Expy with 120,000 miles averaged 16.5mpg highway and 9mpg towing my 16' cargo trailer.

Those numbers did not happen until I sent all the injectors off for refurbishing, changed plugs and boots and complete brake job consisting of pads, calipers, slotted rotors and flexible lines at about 85,000 miles. The injectors/plugs/boots cured a slight rough idle. I really believe at least one caliper was not releasing causing a drag. It was past due for a brake job anyway.
 

Frank Wilson

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Computer says I'm getting 11.8 mpg avg. but I have 35's , so my real mpg has got to be near hyper-mileage level.
 

heston gee

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I would like to be so lucky. My 05 has less than 30K on new engine and tyranny. I think I am sitting at 9 or 10. My driving consists of start truck, warm up a bit, drive 1 mile to school, drop kids off, drive home, shut off. Or start truck drive 1/2 mile to store, leave running while I shop for 10 or 15 minutes then go home.

Now, the 3000 mile road trip, averaged about 17.

Wanna drive the big trucks, expect nothing more than 10 or 11 in town.
 

knewblewkorvett

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Wow, I'm surprised at the low mileage that are being posted. I drive about 75% highway, 25% city. My 2000 5.4 got 13.5-14 mpg combined. My 1997 5.4 gets over 14 mpg combined. It never seems to go below 14 mpg and I check a lot. Why it gets better mpg than the 2000 is a mystery to me as they are identical? PS I just did a trip to Nashville from Iowa in the 1997, got over 15 mpg on every fill up.
 

JVinOlathe

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I have a 1999 5.4 EB with 150,000 miles and I get right around 11 mpg and I drive it very gingerly, not a lot of hard acceleration and coasting when possible. I have yet to find a way to get better gas mileage. No CEL codes or warning lights and drives very nice but the gas mileage sucks.
 

Aspen03

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I'm similar with the 75/25 city/hwy commute. My 2003 Expedition gets slightly worse mileage than our 2003 navigator but only by about .5-1mpg. They both manage about 17 cruising on the hwy and 13.5 with mostly city, navigator will dip into high 12s on occasion but it's also heavier and trying ally with 6 of us in it if we are driving it vs me solo in expedition majority of the time. I don't let it randomly sit an idle, don't frequent drive throughs....virtually never actually, and maintenance is kept up to date. I've had several tanks of all hwy driving finish off at 460+ miles. Thats running it pretty close but never empty. Cruising at 68 is the sweet spot, at least for mine. Taking it to even 71-72 knocks it into the 15mpg range. I'm sure there is tuning work that could be had to improve this, if someone were so skilled. It's just to convenient it drops in that range on both vehicles despite slightly different motors, weights, etc.

Basically the 1st-3rd gen up to 2014 all get pretty terrible mileage based on modern standards . Feel better when you aren't writing a $1100 check each month for the payment on a new one that gets 20mpg.
 
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