Dinghy weight.

We have a 2005 31' Class C on a 2004 E450 chassis and tow a 3000 lb Chev. 4X4 Tracker. I added the 5 star tuner also. We routinely go up 6-7% grades and using the OD On/Off button keep the RPM's in the 3000-3400 RPM range. Gives us about 60-62 mph for 5-6% grades. She will shift as the speed hits about 50 mph and hold it the rest of the climb on steeper grades 7-8%. On a real steep climb we might hit 40 mph but those are really rare. The car was weighed on a Cat scale so we know the weight is accurate. A lot of states require brakes so we had the Tracker wired with lights and a battery charge line. Will be adding brakes in the spring. Cost us about .5 mpg when towing on flat roads.

Dave

we have a 13 hyundai elantra for a towed. Its about 2800 lbs and has a good wide stance and decent wheel base. Have towed it over 10000 miles with the rv, about 400 behind the F350 when I took it in for all day maintenance. Pulled well with both. Yes you will know its back there as you have added about 3000 lbs og weight to the basic vehicle. I also run a 5Star tuner from Mike and it does help as it civilized the transmission and keeps the 5000 rpm cycles to a minimum on hills and stuff. In denver on at least 2 occasions I have been down to 35-45 mph just going over the higher crests. Same thing with wolf creek pass in Colo. but just keep going and you will eventually get back to normal. Check with mike on the 5star tuner for your rv has received good reviews from motorhome and folks running them.

2018 2350 Sunseeker on a 2017 Ford E450 v-10 chassis.
RV setup: Koni FSD rear shocks / Bilstein's in front/ Henderson rear track bar to keep the tail from wagging the dog will be next weeks project, then after I see how that goes, possibly a front steering stabilizer , either Roadmaster or Safety plus.
If need be, next year will be front and rear sways . If that doesn't work, I'm going back to a back packing tent and motorcycle where I started , 125,000 motorcycle miles ago on a full dress Bee-mer.


Chev Sonic automatic

Using my system the way it's set up, I can tow the car with any TV capable of the weight and a 2x2 recvr., and 7-way plug.

Blue ox Alpha tow bar

Hard-wired harness under the hood
(Drilled separate tail light bulbs in the rear for running and brake lights . 1157 bulb, I didn't have to mess with the OEM wires)

Brake Buddy II , assists with braking.

So far, no problems climbing hills east of the Mississippi but my rig is only 12,500 rolling down the road plus the Sonic at approx. 2800-3000# depending how much fishing EQ plus the canoe and gear .
Interstate grades are easy but a few smaller backroads were more challenging at times.
I would think a trip in the Rockies would be more of a strain but doable.

I put a lot of time into a choice of a toad, and paid close attention to comments from other user's about their toads. There's only a 300 pound difference between your toads, so it will not be that much of a major difference. I separate toads into 3 general weight categories; 2300 lbs, 2800 lbs, and 3800 lbs. I chose the middle of the pack Kia Soul at 2800 lbs. In general, with a class C, it seems a good many folks really feel it when they get to the 3800 pound toads(Jeeps etc), and some go back to the 2800 pound range or lighter. Your 03 doesn't have the advantage of the newer transmissions with their added gears. If your disappointed with the performance, you could drop lighter to a sub-compact(2300 lbs), or put in a Gear Vendors Overdrive which will give you more gears for mountain climbing. If you don't run with full water,you save the weight difference right there.