"Calif Bill" wrote in message
m...



They must of improved the 5.4L from the 1999 Expedition I had. Dang gas
hog, without a lot of mountain tow power. Most milage I got was 16.5
returning from Los Angeles on I-5 and lots of slow traffic. Do not think
I ever got over 65 mph in a 350 mile trip. My Duramax gets about the same
mileage towing at 55 that the Expedition got in normal freeway driving.
About 15.5 mpg. Just returned from a trip to Burney, Calif last Thursday.
Towing boat (4400#), and the popup slide in camper (1400#) and going over
some 3000' hills, I got 13 mpg for the trip.


The 5.4 is an old engine design, but is pretty bullet proof. It's also been
improved upon since then.
My wife had an early Navigator (2000) that, in addition to a horrible
suspension system, had a 5.4L that couldn't get out of it's own way. She
currently has an '08 with the same engine, but it is reasonably peppy,
having significantly more horsepower than the earlier one. They have
vastly improved the suspension system on the Navigator also. It's actually
very comfortable to drive.

I think the Navigator's 5.4L is a higher output (horsepower wise) version
at, I think, 340 hp. My truck is only rated at 300 hp.

Eisboch