coadman

We are looking for a 2001-2003 Expedition. We used to have a 1998 Expedition Eddie Bauer with the 5.4 litre motor, and like the drive, ride, and room for 7, if needed. High mileage made us sell it two years ago, and purchase a F150 supercrew. It's a really nice truck, but my wife really misses the extra passenger space, so we are shopping once again. If I remember, our old '98 would only get us an average of 14 mpg. I was wondering how much increase we could expect in fuel economy if we went with a 4.6 as opposed the the 5.4? Only thing we ever pull with it is a small popup camper occasionally. Thanks for any input.
coadman

 

redneckf150

My wife had a 2003 with the 4.6, and she probably got about 14 mpg. She now has a 2005 with the 5.4, and we recently got 17 mpg on a trip. The 5.4 has a lot more accelleration than the 4.6, and has apparently been re-worked by Ford to be more fuel-efficient. Another thing different between these vehicles is that the 4.6 had 355 rear-end, and the 5.4 has 373 rear-end. The 373 should make the thing less fuel efficient according to the books, but it definately explains the increased pickup (in combination with the larger motor). So, in a nutshell, the motors are a bit more fuel efficient than before, but since when did Ford ever sell a vehicle because of fuel economy? They're valved differently, and thus have more low-end torque, but this comes at a cost of less MPG. Life is short: get what you want!

danketchpel

I think the 4.6L is a bit too small for the Expy.

I'd definitely get the later 3 valve 5.4L motor. I have the older (2004) 2 valve 5.4L and it's a pretty good engine, especially for towing. We get around 16-17mpg fwy running light and 13-14mpg towing & loaded. That's on crappy CA gas. I've seen as high as 19mpg fwy on New Mexico gas.

The later 3 valve 5.4L has variable valve timing which improves HP, torque, and mileage, it's a win win situation. I believe it's rated 2mpg better than the old one so you'd be looking at 15 - 19mpg realistically. Not bad.