Power mod needed to help trailer towing?

I was wondering if putting in a power box or a power chip will help me with
my trailer towing problem? I have a 2002 Jetta TDI (1.9) and it works very well and it is the first car I really enjoy driving no matter what the distance is.
My problem is when pulling my trailer loaded with my dirtbike and 4 wheeler the car slows down from 75 mph (with cruise set) to 55-60 mph on some of the hills we have here in Kentucky and also hills in Tennessee.
I'm sure someone will say get a more powerful vehicle but frankly if I can get the Jetta to do it, I want to use this car. On a recent trip to Tennessee with trailer and car fully loaded, I still averaged 28 mpg and I think that is amazing considering I was pulling 1400 lbs and had the car loaded with 150 lbs of camping gear.
My Dodge RAM I USE to have got 8 - 10 mpg so the Jetta is a necessity for me. I don't want to abuse the Jetta because I plan on keeping it for 10 years or more. It does do a great job pulling the trailer and load other than slowing down, (which is real fun with a semi-trailer on your tail).
I would appreciate any info you can give on the power chips or boxes-
Do they work and will they help me with trailer towing?
Thanks, Don Wittbrodt, KY

Ive pulled a 580lb trailer, two 430lb sportbikes and a solid 100 to 200lbs of gear up 9% highway grade inclines going 85mph and could still easily accelerate in my 02 Jetta. All I have are PP520 squirters. I was on I75 driving through KY headed down to the Tail Of The Dragon also. (Shamless Plug) I still manage to do about 28 to 30mpg with my setup.

I assume its an open top trailer? If so try to have as little drag possible. Point the toys forward and cut down on large flat areas getting direct exposure to wind. If there is a folding gate on the trailer that sticks up in the back, take it off for the trip and figure out a different way to unload the toys.

Have you ever cleaned out the intake and some of the other basic stuff suggested here?

Here is the towing rig. Notice the gate that I removed. You would think that the gate would not be to much of a drag problem but it makes a MONTSEROUS difference.

I agree with the suggestion of making sure your car is well maintained. I've pulled some pretty "heavy" (1800 lb, 5ft wide, 7 ft tall, 8ft long) with my car in stock power form (with the taller0.681 5th gear). The only issues I've had were having to downshift on some of the mile+ long 6% grades to maintain speed (65 mph). Otherwise, just set the cruise and forget it (at 75 MPH).

Unless you're a lot heavier, a lot bigger or going up much steeper hills than what I described to justify your slowing down, check the basics: Intake/EGR clogging, fuel filter, air filter, snow screen, injection timing, tire pressure, brakes dragging, etc. These are things that need to be done before any power adders anyway, so no reason not to do them.

If you're properly maintained and still need/want more power, I first suggest boost and EGT gauges, then injector nozzles and some sort of chip tuning (RC, Alligator/Kerma, Tech9, Ultronic, etc). I would seriously consider upgrading the clutch as trailer pulling is harder on drive line than most any other kind of driving (except side stepping the clutch). These things should allow you to keep an eye on EGT's while allowing extra performance you need.

Other performance suggestions to further improve durability and performance: Exhaust, intercooler, intake & intercooler piping, VNT17VB turbo.

You most likely have a bad MAF sensor.

Ahh - I knew I forgot something

That's another thing to check

yeah make sure all is working well with the car but I want to add that these cars can haul very well, just did a roughly 400 km trip with my newly built 4 x 8 covered trailer and full tool box, mini fridge and some supplies in my car along with the usual roof racks and cargo carrier on top. Going the Coquihalla Highway and Okanagan Connector certainly not the flatlands routes with the cruise set at 120 km/hr it drove like a dream and hardly went slower up the big hills.