Whats normal for these trucks I got a 99 Expedition 5.4 with about 105000 on it and im getting between 8.6 and 11.7 MPG. Is that normal if not how can I getbetter mileage??

 

It all depends on several factors, like how you drive, what type of driving you do (city/hwy), the gearing you have, etc, etc.

I have pretty much the same truck as you and with 3.73 gears, about a 70/30 mix of highway/city, and driving with a fairly light foot, I'm averaging about 12 or 13 mpg daily driving. Before I moved last year, my daily commute was about half as much, so more city driving and included a fairly steep hill and I was averaging around 10/11 mpg.

The best thing you can do to improve milage (which still isn't much) is to baby the throttle. Keeping it under 2000 rpms seems to be a major key.

 

In my 2000 xlt 4.6, I get 12 highway and like 9 in city...ROUGH! I have read ideas on improving mpg on posts here, but they're over my head. One included overriding the a4wd, so it is in two-wheel drive for normal driving conditions. I'm sure these guys have found other ways too....

I was thinking torque-wise, that the 5.4 would get better gas mileage because of the weight-to-torque and power ratio...I guess this isn't the case....

Of course, regular maintenance and tune-ups are important, and overdrive is supposed to actually SAVE gas when you leave it on all the time (except when towing).

Just a few things I've read....

 

Hello I have a 99 w/ a 5.4 and I avearge 11/12 highway, and 9 or less city, it can be expensive but beats owning a minivan to haul kids in!

 

I have a 2000 XLT 4.6 with about 148K on it. I get about 20 mpg on trips and 15 mpg in the city. My son has a 1998 EB with the 5.4. He has about 140k and he gets around 18 on a trip and 13 in the city. I've had nothing done to the engine except for normal maint and neither has my son. We both drive very light footed.

 

Howdy folks,
We took our Expy on a road trip this weekend. I kept the RPM's below 2K, more like 1800 which is roughly 63mph. It was hard to do as I like to drive at least 70mph on the highway. However, doing this I got about 18mpg. In the city I am getting around 10mpg.
I am looking at mods, less restrictive air filter, new plugs and wires, and a tuner (edge evolution). Also, at my next oil change I will be switching over to all synthetic fluids. I'll let y'all know if that helps at all.
Craig

 

Ok I guess I got my answers... I have a rather heavy foot i just put new plugs oil change with mobil 1 I just wanted to make sure mine was doing ok the highest I ever got was about 18 mpg butt hat was on a highway with the cruise control on. I guess not wanting to own a minivan i have to deal with the mileage. Usually the average is like 11.4. Thanks guys...

 

That's pretty decent mileage. Are those 4X2s? Is it fairly flat down there in AL? And is the temp usually above 60 degrees?

 

I have an 03 4.6. Added a cold air intake, electic fans (+1.5 mpg + noticeable hp), custome tunes (noticeable + hp), underdrive pulleys (+1-2mpg, + noticeable hp). Before pulleys (latest mod) I got 19 mpg in summer. this winter after pulleys, I got 17.5 mpg highway (clarification - winter usually goes down 2-3 mpgs' I expect to easily top 20 when summer gas comes out again). Used to get about 15mpg stock (in winter). I average 15-16 city/hwy in winter now.

I run 1800 rpm at 70mph. The uD pulleys made an amazing difference in accerleration as did the e-fans. The tuner made it into a whole new truck. It is fairly quick and powerful as opposed to stock. I would never undo the mods. it should come like this from the factory. I can jump from 40 to 70 mph for passing in just a few seconds - much better than stock!

 

This may seem pretty basic in light of all the mods discussed to this point, but what kind of tires are you using 99EdeBauer?
I had a set of tires with a really aggressive tread pattern when I first got my truck ('97 5.4). They looked nice, but my gas mileage went up almost 30% (across the board) in going to a more conservative tire (Yokohama Geolandar H/T-S G052).
Just thought I'd throw my 2 cents in.

 

Actually we live in the hillier region of AL. It's not as bad as Colorado but it's quite a bit hillier than when we lived in the N.E. Both of these vehicles are normal 2X. I guess we should be real happy with the mileage we get.

 

In highway driving, I feel I get better gas mileage by NOT using cruise control. I can nurse a lot of extra distance out of the expy by coasting it a lot. It has a lot of mass and if you back off the pedal, it will continue at a high speed without the foot on the pedal. It seems like cruise control feeds it a contstant stream of gas. I bet foot-driving versus cruise control saves 10-15% on the highway.

 

I just got 17.4 from OK city to Blair NE (470 miles). Part was ice (slow) and part was secondary roads but still 17.4 MPG. I think the DRIVER has a LOT of influence on MPG.

 

I use the bridgestone dueler at revos... I love the tires great in the snow no noise... Why do you ask??

 

I have a 98 with 3.31 axle ratio an 54 l engine. My mileage varies between 11 and 19 mpg. If I keep th highway speed at 65 I can do 19 mpg. When my wife sits at the bus stop with our son and then drives the five miles to work she averages about 10-11 mpg during a New England winter.