2,500 mile trip report:
I made two trips between Dallas, TX and Fort Knox, KY with a loaded trailer. The first one had a GCWR of about 19,200 lbs. The trip back to Dallas was with an unloaded albeit heavy trailer and a GCWR of about 13k lbs. The second trip was a GCWR of about 17,600 lbs. The truck did wonderfully! After the trip, I have no issues with the power capabilities of the truck. The best Fuel mileage was 13.3 mpg and the worst was 10.7. On the best mpg, I was driving around 55 mph. On the worst, I was hauling at night on open interstate at around 75-80 mpg over hilly roads downshifting out of OD often.
I've learned that my favorite speed to tow is 65-70 mph. Towing slower than 60 on long gradual hills resulted in hearing what I believe was detonation. I didn't let the sound go more than a few seconds, but it did sound a little more like a hammer with each stroke, but not bad. I suppose I was lugging the motor a bit, and after I heard and confirmed it to the best of my beliefs, I stayed away from OD at those speeds. I like 67-68 mph because it brings the tach up to just under 2k rpm, doesn't lug at full throttle in OD, and gives me a buffer to see if the motor can maintain speed or if I should downshift.
I've learned that I am perfectly happy with the stock tune on the truck. The mpg is where it should be. The power in 3rd gear, up to 60mph, was more than enough to get up the steepest hills I've encountered (off of the interstate). I could still see upgrading from the model year 2000 stock 235hp tune to the '01-'02 275hp tune if I can get it for free at a Ford dealership, but see no reason to pay for a chip. So I probably won't. I do think an EGT gauge would be nice, even with the stock tune. I'll bet that I would've seen something on the gauge when I may have lugged the motor.
Getting the trailer brakes was definitely a smart plan, and I absolutely give the SP Perfomance EBPV exhaust brake 2 thumbs-up! It was so useful in traffic and on downgrades. The way it automatically opens up when the gas pedal is touched is wonderful, and it never glitched or failed to operate in any way. With the exhaust brake, new trailer brakes, and the relatively recent truck brakes, I had plenty of stopping power for the interstate.
I have to say that I'm not the biggest fan of the Activator 2 or any time-delay based electric brake controller. The controller did its job very well, and got the trailer stopped when I needed it to, but I would much prefer a controller that applies the trailer brakes based on the pressure I apply to brake pedal instead of a timer. I found myself often softly pumping the brakes, and/or adjusting the the controller in slow traffic where I only wanted light braking and gradual speed reduction. I only needed to brake at 70-80% twice on the trip, and for those hard stops, the brake controller did just fine. I'm probably too cheap to upgrade, as I don't feel that this is a safety issue, just a minor annoyance.
Initially, the Curt Weight distribution hitch gave me some trouble as it wasn't doing a good job distributing load. However, this was not the fault of the manufacturer. I finally realized that it was sold to me as a showroom model without the bump stop needed to keep the angle of the hitch right. I also ended up upgrading from the 5-10k lbs spring bars to the 10-14k lbs spring bars. I put all of the spacers supplied with the bump-stop in and maxed out the spring bars, leaving 5 links as instructed by curt to avoid any binding. Then, I was able to get over 3800 lbs back on the front axles. This nearly leveled the truck out. It normally rides unhitched at about 3,900 lbs with me in the truck. Leveling the truck absolutely made a noticeable improvement on the feel of the truck The GVW of the truck stayed at less than the 8,800 lbs GVWR of the truck on all trips. I never came close to overloading the truck's rear axle. The trailer did weigh about 12,300 lbs on the first trip, even though its GVWR was only 10k. Still, this trailer's tongue weight was so high at ~1,700 lbs that there was only 10,600 lbs on the trailer axles, each of which was a 5,200 lbs dexter.
Other than that, the only minor issues I ran into was that the fuel filter was leaking. The mechanic who installed it put the o-ring in upside down I believe, and I noticed it because I could smell diesel at idle. It was giving me a headache, but this site helped me diagnose the issue, and I replaced the cap, o-ring, & filter with a Wix, sprayed down the engine bay at a self-service car wash, and I'm pretty sure it did the trick. Also a headlight went out, and I haven't replaced it yet. The truck's at over 155,000 miles now, and now I'm confident I didn't buy a lemon.
Overall, I am very very pleased with both my 16 y/o Ford truck and 20 y/o Wells Cargo trailer. They are still getting the job done.