New to the forum and had a couple of questions for you. Did a search and did not find exactly what I was looking for. Recently bought a 10 x 6 enclosed trailer to haul my motorcycles in. The trailer is about 1400lbs and the bike I had in it was 650lbs. Add another 300lbs of stuff and we had I had about 2400lbs behind my 98 Expedition (EB), 5.4 L, with drop in K&N. For reference I have been getting about 10 –12 mpg around town, not good. This trip I got about 8-9mpg on the highway, with the trailer. Spent a good part of the time in 3rd due to the trucks inability to stay in OD. Even on flat roads. Seems a bit extreme based on the relative light load. Truck seems to have a loss in power over the past year.

I was looking for places to start as to possible problems. I have 75000 miles on and the truck is well kept, and has had no problems. My first thought is having the injectors cleaned and then possibly the plugs changed. Any input would be great.

 

I usually get 13-14 around town with my 03 Expy. And about 11 MPG towing 5000# worth of open car trailler and car on the hwy @ 70 MPH. I suspect that your in ability to stay in OD is more because of the frontal area of the enclosed trailer (i.e. brick) than the weight of it. Also, do you know what gears you have? I know some of the Gen1 Expys came with 3.31 gears which might hurt you trying to tow in OD.

 

A tune-up & injector cleaning certainly wouldn't hurt. You might start off with seafoam or Lucas. I hear both are good products. Also make sure your tire pressure is correct. Were there strong headwinds where you traveled? Was mileage same coming and going?

 

I have the 3.73 gears and have since determined the wind factor to play a large part in the towing of an enclosed trailer(brick). Pulls great in 3rd by sucks the gas. OD is fine without the wind aginst me. Is it common to be out of OD with only 2500lbs or so behind the truck, that is, am I getting what I should expect out of the truck? 3rd gear, 9mpg, OD occasionally? Seems a bit drastic for the weight I am pulling.

 

Any idea if anyone makes some sort of an airdam for the top of the Expedition, to help get the wind up over the trailer?

 

I don't know where it came from, but I saw one on an Expedition today; it was molded around the rear liftgate (on the upper portion of it) and angled upwards. My experiene with Expeditions is very new, so maybe someone else could point you in the right direction. (But having seen it, and then read your thread, I can see where this may be beneficial in your case).