I have a 99 expedition, 5.4 engine 4X4. It has 163,000 miles. We tow a 2012 Primetime tracer with a dryweight of 6000lbs. The expy is rated to tow 7500lbs, so we are pushing it's limit. I am no mechanic so I need your help. What can be done to increase the the trucks tow capacity? I'm not sure what rear end is in the truck. Thanks Bob

 

Buy a larger capacity vehicle.
I know it sounds trite.
Your Ex is rated to a max GVWR of 13,500#.

These vehicles are built of parts engineered for a certain strength.
In order to go heavier you have to go stronger.
Suspension, tires, brakes and driveline upgrades are just the beginning.

Find a '05 6.8L Excursion and;
with the 3.73 rear end and the trailer can go to 9600#s / GVWR 17,000#.
with the 4.30 rear end and the trailer can go to 11,000#s / GVWR raises to 20,000#.

One quick GVWR increase is to go with smaller wheels.
Going from 17" to 16" rims will gain about 500#.

 

I agree, more towing capacity = bigger truck...

 

Would a tuner work? If so are there any drawbacks to a tuner?

 

Towing capacity is a measure of the vehicle weight, axle ability, and the frame strength. More power will help pull your load easier, but not increase the load you can pull. If anything, more power will lessen your capacity by putting more stress on your drive train.

 

I went from a E-150 with a tired old 5.0L to the E-350 in my signature.
I would pull the hills at 35mph with the 5.0L straining to haul a 19' travel trailer.
The 6.8L pulls a 30' 8,500# TT almost as if it wasn't there.
A tuner will be a good addition to any strong enough vehicle.

 

Honestly I'm not sure why you are worried. If you are under the tow limit and are not having issues getting where you are going then why worry? And no there is nothing that is going to upgrade your tow rating, a tuner is just going to give you more power(maybe) but not a higher tow rating. If you have to have a SUV that can tow anything, the Excursion is your only real option, just make sure it is not the 5.4L and at least has the V10. If you are going to be towing a lot then IMHO, the PSD is the only way to go but the V10 can tow a LOT as well.