Depends on the year, engine, transmission, and body style which you fail to list.
See link.
You should be getting 10-15 mpg depending how you drive it
about 12.5
15 miles to the gallon 15 miles to the gallon
35 Miles per gallon.
A little more information please ( size of engine , automatic or manual transmission , rear wheel drive or 4x4 )
Ford F-150 trucks are rated 500,000 miles but it all depends on maintenance.
about 6
26
Anecdotal repots suggest it gets around 15 miles per gallon.
The 1999 Ford Expedition gets about 16 miles per gallon at its very best. On average this vehicle gets 12 miles per gallon in city traffic.