Fuel Economy - First Long Tow

[boostedh22a]

Well friday me and a buddy started on a trip from Indianapolis IN, to just SW of Dallas, Texas to pick up a car

I just got back and I'm a bit surprised with the fuel economy.

I have a 2000 Ford Excursion 7.3 TD. It is a 4x4, and has a 3.73 limited slip axle, stock sized wheels/tires

To the details, the round trip was about 2000 miles. We averaged right at 9 mpg. Best tank was 10, worst was 8.7.

The reason I'm even posting this is, my old truck, a 99 F250 7.3 TD 2wd (and I can't remember the rear axle ratio), stock sized wheels/tires, with the same size trailer and load, got around 12.

For what it's worth, I was pulling a 24' enclosed trailer, with a 2500 car. I drove between about 65-75 the entire time. This is also the first time I have really pulled in cold and snowing conditions as well, don't know if that has an effect.

Does this seem normal?? With diesel being $3.80 (this trip at least) I really would like to find out if there is something wrong, and if there is a way to increase my fuel economy.

Any comments welcome.....thanks!!!!

[AJF]

Seems kinda normal from what Ive seen maybe a bit low. Were you in a lot of hills country. Also 4x4 will never be as efficent towing as a 2 wheel drive, colder conditions and winter fuel will have an effect as well. Someone else will chime in here soon as well, I'm sure.

[boostedh22a]

It wasn't too bad, there were a few hills, but nothing like I have towed through before with my old truck.

[jamstoyz]

do you know the weight of your trailer? sounds about right tho. try keepin it under 65 and you should see a difference. also do you have any kind of chip or tuner on your psd? if not that should help you out a little. i use to tow with my old 7.3 and 6.0 and got around 12 to 14 mpg. my toy hauler weighs close to 10,000 pds loaded. my worst was 6 to 8 in the mountains.

[boostedh22a]

The trailer dry is 3200lbs. The car was about 2500 or so. I would say the total weight with the car/trailer closer to 6000lbs.

Would taller tires help?? It seems like this truck is higher up in the RPM's when I'm cruising than my old truck was.

I don't have a tune, just a K&N intake system, and thats it.

[99bigred]

on the highway taller tires do help but around town they hurt. depends on how mugh highway driving you do if it is worth it.

[boostedh22a]

Well day to day I'm usually just around town, but when on go on trips, they are usually long hauls.

However, I would say that about 60% of my driving (mileage wise) is local.

[99bigred]

with 35" tires and unloaded i will get upto 25mpg while cruising at 60. if i step it up to 70 it drops to about and 18, by 75 it is down to 15. all those are the true speed with the bigger tires and coming from my scangauge trip computer.
it is obvious that anything over 60 and the mpg drop dramaitically.

[boostedh22a]

^^Interesting. Maybe I need to just slow it down a bit and allow more time for travel....haha

[99bigred]

yes it really does help. going to the desert one time it was about 90 miles eachway, going it was between 75 and 90 the whole time and it only averaged 12.5 unloaded. coming back it was a slow cruise between 55-65 and it got 16.