mileage/range

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egeller

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Typically, when I fill up, it says that I have between 480-500 miles to empty, however, recently, it only says about 360 miles to empty when I fill up. Additionally, I've been using my trip to track how many miles between fill-ups, and I'm only getting between 260-300 to a tank. It says that my MPG is 11.4. Is this normal?
 

GaryH

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I typically get between 15.4 and 16.4 in my '03 Eddie Bauer with 5.4L engine. About 50-50 city highway driving. Are you getting a CEL or SES light, whatever they call it these days? How many miles are on your Expedition? When was the last time the plugs and coils were changed? Have you had the injectors cleaned?
 
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egeller

egeller

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2003 Eddie Bauer
5.4 2v
259500 miles
No lights
No idea when the plugs or coils were changed
Would they affect the fuel mileage?
 
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kep5niner

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The same year and approximate mileage on my 5.4 2v. Plugs could improve fuel efficiency, as part of general maintenance and tune-up items - air filter, fuel filter, etc. If the COPs are bad, you will get codes such as cylinder # misfire. If the status of your plugs is unknown, you could pull one or two of them, check for condition comparing it to the representative pictures of plugs in the front of a Haynes manual. What your plugs look like can tell you what’s going on in your engine. Also, check the gap. If they’re worn out with a large gap, fuel mileage will suffer.
 

Broncoholic

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Typically, when I fill up, it says that I have between 480-500 miles to empty, however, recently, it only says about 360 miles to empty when I fill up. Additionally, I've been using my trip to track how many miles between fill-ups, and I'm only getting between 260-300 to a tank. It says that my MPG is 11.4. Is this normal?
If you recently had the battery disconnected, the computer resets to a factory value for fuel mileage and the "miles to empty" is high. The more miles you drive (hundreds, or a few tank's worth) the closer to actual the miles to empty gets. We almost ran out of gas in the backwoods of a road trip because our M to E was way too high after disconnecting the battery. With my lift and tires and 90% city driving, I average just under 11 mpg.
 

chuck s

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Manually computing fuel use (hard to type "economy" when dealing with the Expedition) is simple grade school math -- or your iPhone.

Recommend the "two click" fill for consistency. Fill until the pump "clicks" off for the first time, wait 30 seconds, reactivate the pump until is "clicks" off for the second time. Read and reset the trip computer. Grab the receipt and do the math. Do this for a few fills and compare to the car's computer.

-- Chuck
 

BigRed2004

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Lower fuel efficiency in a large vehicle can have a variety of contributing factors. Some of things could be happening without a check engine light triggering because they aren’t bad enough yet. But here are things to take into consideration:

What are your driving habits like?

Do you take extremely short trips that don’t allow the engine to get to temperature before turning it off again? Hot oil moves the best and less likely to create sludge/varnish deposits that restrict flow and efficiency. Reducing internal system parasitic loss.

Do you gun it at a green light and treat the vehicle like a sports car? And or brake hard/late? Rapid acceleration requires more fuel than gradual acceleration. Braking hard/late means you use more fuel longer than a gradual deceleration.

Do you check the tire pressure regularly to make sure you are at the optimum level for the tire? Not just what the vehicle recommends, but the tire manufacturer. I run my tires around 41 PSI instead of the recommended 35 PSI. Tire manufacturers know what their products can do. Vehicle manufacturers give a standard recommendation without know what tires you will be using at any given time.

What modifications have you done?

Do you have unnecessary weight on the vehicle In the form of a skid plate, ram bar, HD roof rack system?

Do you have unnecessary weight being carried in the vehicle?

Are your tires and wheels factory spec or aftermarket? And if aftermarket did you have then scaled proportionally to account for the factory sensors?


There are so many things that can add up to worse fuel efficiency. Weather is also a factor and using the AC. This is not to say we need an entire vehicle history breakdown to answer your question bette, but the amount of information provided isn’t enough to really help per say. I’ve seen my MPG drop to 12 in the summer with consistent 105+ temps, heavy AC use and lots of stop and go city driving.
 

tdfuller

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Owned my 03 Expedition 5.4L V8 - 20 years - sole owner.... If battery is disconnected fuel range will read artificially way too high until driven a while.... Even if plugs are new, coils are fine, pray over the vehicle, and drive 100% highway... you will never get over 450 miles even on a full 27 gallon tank. Just won't happen, unless the whole trip is downhill or has a big tail wind.

I get about 12 MPG living in Charlotte, with 90% city driving, using normal 17" tires - Bridgestone Dueler H/L.
 
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