On the 17 if it has the factory trailer brake controller in dash it has the heavy towing package. not sure of the other years, probably the same. something good to look for would be the 3:73 axle which also gets limited slip{ door sticker code 3L}. keep in mind that for the 9200# rating on trailer weight that is with weight distributing hitch. I've only towed with mine a little so far but the only thing I don't like is no extendable tow mirrors available, or at least I haven't found any yet. Jim

 

 

I don't have a comparison of mileage but I would say it will certainly make some difference.
wow I had no idea that pic would be that big, sorry some what computer challenged . the brake controller is near center of pic below the dash vent, just above 4wheel drive ****. Jim

 

I have a 15' EL 4x4 with the tow package and 3.73 gears. I tow a 5000# boat twice a month 120 mile round trip and it does great just set the cruise on 70mph and I still get 10-12mpg. Empty we average 16-18mpg.

 

 

I had in my head that 373's were a part of the tow package but my window sticker shows separate line items and price for each? with the 373's at 70 the RPM's are only about 200 below the peak torque RPM so it should make a big difference towing at highway speeds. I'll find out tomorrow, I'm headed for northern Ontario with about 5K in and behind it. I'll post my impressions next time I get close to internet. Jim

 

I thought the 3.73 were part of the package but an option if you didn't have the tow package. I think my towing mileage is a little better than average with that weight since my boat causes very little wind resistance. It's the same height and width of the truck and shaped like a V. I'm sure mpg would drop off significantly it it was 5K of box trailer.

 

The 3.73 gears are standard on the EL 4x4 .
3.31 gears on EL version and 4X4 regular.

 

I wound up purchasing a 2016 Limited which of course has the tow package. We love it! Thanks for all your good info!

 

Same with my 2015 XLT. Also if you can't find a re print of the window sticker you could ask dealer for a "BUILD SHEET" Basically what the factory would use to install the options during assembly.

 

Heavy Duty Trailer Tow Package
$1,570 S4
RemoveA beefed-up Expedition ready to tow its best-in-class rating of 9,300* lbs.
• Heavy-duty radiator
• Pro Trailer Backup Assist™
• 3.73 electronic limited-slip differential
• Integrated trailer brake controller
• Two-speed automatic 4WD (4x4 only) with neutral towing capability

*Best-in-class rating of 9,300 lbs requires Expedition 4x2.

Maximum Towing Capacity:
Expedition 4x2 - 9,300 lbs.
Expedition 4x4 - 9,200 lbs.
Expedition MAX 4x2 - 9,000 lbs.
Expedition MAX 4x4 - 9,000 lbs.