[Sicapo]

2012 Jeep Grand Cherokee V6 (with factory installed towing package)
2013 Passport 195RB (3880 lbs empty)

Although the Jeep is rated at 5000 lbs towing capacity,
never had any problem so far (5000 mi)

Usually drive at 60 mph (3000 rpm) on highway.
It can shift in OverDrive (2200 rpm) when there's no wind.

Didn't had any problem crossing PA mountains.
On some steep hill, I was only going 45 mph as I didn't want to push the engine too much.