Realistic Aftermarket Rating?
I own a Touring L without the factory tow package. I added an aftermarket CURT Class 3 hitch.
As has been mentioned, this means I don't have the anti-sway software, the 220a alternator, nor larger radiator.
That being said, I strongly suspect the realistic tow capacity of my aftermarket hitch is much closer to OEM than Chrysler is saying. Let's look at the differences individually:
1) The software, while undoubtedly helpful, doesn't increase or decrease any towing capability, other than ensuring the vehicle is more stable during unstable movements.
2) Likewise, the alternator doesn't affect anything about the load. It would help keep the battery topped off during times of constant engine cooling fan use and 7pin electric braking (in addition to the standard vehicle energy use). But again, nothing affecting towing capability. As an FYI, the standard one is 180a, the heavy duty is 220a. So if you're not driving with your high-beams, maxing out the interior 110v inverter, and bouncing with the 20 speaker system on max, I don't see any risk here.
3) The larger radiator. This certainly can make a difference. But here's my argument: It's only .3 quarts larger (13.4 vs 13.1q) as far as coolant capacity goes. Further, it's not a transmission cooler. It's just to keep the engine temperature down. Therefore, if you're not towing 85mph on steep grades in 110 degree weather, I'm not seeing this as a risk either.
I'm going to be towing a load approaching 3000lb in a few weeks, but it'll be in temperatures of 30-60 Fahrenheit. Besides being without anti-sway, I'm not anticipating any issues that I wouldn't already be expecting if I had the actual tow package.