ok, so after ANOTHER THREAD I'm being told my gas mileage is horrible on my 2001 Expedition 5.4L V8

I was getting around 300 miles between fill ups... then suddenly the Service engine light came on, and was told I had an O2 sensor out, which I couldn't afford to repair at that time, but what I have now noticed after several tanks of gas is my gas mileage has gone up to around 350-380 miles per tank... so I'm getting about 2 additional miles per gallon. I was stoked. Another poster in that linked thread above is explaining that even at "default" 12 miles per gallon - I'm still about -3 under par.

SO: What can I do to improve gas mileage? I'd be a very happy camper if I could get 450 miles to a tank! I'm seeing other people claiming 15 miles per gallon - and I'm no where near that.

Basic information about my truck:
2001 Expedition 5.4L (EB if that matters)
about 185k miles.
I've owned it for about 2.5 years, about 40k miles (give/take). I didn't get any service records when I bought it, so I've done what its needed as I can afford it. Shocks, Brakes, Air filters, Mass air flow, spark plugs, etc.. I regularly change the oil.

HELP ME OBI-WAN KENOBI(s) -- YOU'RE MY ONLY HOPE.

 

What is your MPG, not just how many miles you go on a full tank.

 

I'm getting around 10 mpg

 

In town, highway or combined. I get 11 mpg in town and 15 on the highway. 1999 Eddy 5.4 4x4. Thats as good as it gets. I also have the 373 axle ratio.

 

I guess I should add mine is a 2x4 NOT 4x4

 

A heck of lot depends on your right foot. My 2000 Navigator 5.4 4x4 with 178K on it and me driving is averaging 13.5 right now mixed city/hwy driving. With my wife driving it's consistently mid 12s. It would probably be better without the 22"s on it...

 

I wish I could get over 13, lol

I average just under 12 in mixed driving

2000 Nav 4x4, all stock - use Premium gas

 

When gas hit $4.35 a gallon some time back, I took out all excess weight from my truck (97 EB Expy 5.4L 4x4). This has the removable 3rd row seat so that came out as well. I then took off the overhead rack and removed my radio antenna (to reduce wind drag). Finally, I reduced driving speed to 60mph on the highway (from normal 70mph). Also, I frequently ensured my tires were all inflated at the correct pressure. With all these changes, the trip computer showed me at 16mpg. Nowadays, I'm getting more like 14mpg according to the TC as I'm driving at 70mph again. Roof racks, antenna and 3rd row seat are still in the garage.

HTH

 

I have a 2000 Expedition with the 5.4 liter 2 wheel drive. (K&N drop in filter / cat back flowmaster exhaust) I get 11-12 mpg in town and average 17-18 highway. The best I ever got highway was 19 mpg when I went from Vegas to Reno, I was driving 70 mph on cruise most of the way. I'm sure my wheels/tires hurt my mileage a little as I have 275/55/20's

You are not going to do much better. These things suck gas.

 

My '03 5.4 2WD gill give 10-12 in town and 19-20 on the highway. The bride drives mostly in town and I drive mostly while on the I-state. I use the cruise and set it 3-4 mph over the posted limit. Pulling the travel trailer is another story, we get 9 and change at 65.

 

I'm the second owner of a '97 Eddie Bauer 5.4L 2x4, 201k on the vehicle, 120k on the motor (replaced by a Ford dealer to the tune of $5,000 because the last owner wanted a "new" motor, not a reman???). I got the paperwork from the motor R&R with the vehicle and I couldn't believe it. Anyway, off the lot the beast gave me ~10mpg city and 13mpg highway. No heavy foot, just LOTS of mountains. Did a full tune-up but didn't notice much of a difference. What DID make a difference, however, is when I decided not to buy the $300 aftermarket intake kit, but rather make my own from what was already on the vehicle.

Took the GIANT filter housing apart, used my Dremel to cut the half that the filter goes into down to just the ring that would hold the filter in place, and still let the clamp tighten it up. So now, I had a filter with no housing around it. Put a K&N filter in place of the paper one, redneck engineered a heat shield (not the prettiest, but it works) and used 2 pieces of 5" diameter flex-tubing (kind of like dryer vent, but rubber) to run from both the inner fender and just underneath the front clip up to the redneck air box I made. So now, I'm getting cold air coming in, blocking the heat from the motor, and besides the filter, it cost me nothing. What it did do, though, is got me from 13mpg on the highway to 18mpg. City still hovers around 11-12, which is a little better, but 5mpg better without spending an arm and a leg made me happy.

 

I'd like to see a pic of this mod. Sounds like it an easy one to try.

 

x2 that request

 

anyone know of a good Android app for keeping accurate gas mileage stats?

 

I am also getting ready to cut the factory housing down to just the rim to hold the K&N filter I bought on. Was wondering if anyone else had every done this. It is still not as good as a whole kit due to the mass air flow sensor still having a narrow opening that the kit does away with.

Im also getting ready to install a Gibson muffler (95% free flowing but still keeps it quiet). I did this air and exhaust combo to my 2002 F-150 supercrew 4x4 I had years ago and saw several mile per gallon increase. Believe it or not I was getting 18 mpg (mostly highway) with it.

I'm also a big believer in getting rid of the weight. Took off the spare tire, third row seat, front tow hooks, and other small non essential items which always helps. Along with a light foot.