2011 LR4 HSE Lux does a very nice job of pulling a 2 horse trailer with electric brakes, using the OEM hitch. However, I definitely feel the weight. Going up a long steep winding gravel driveway I appreciated low range and traction control, but it handled just fine. I wouldn't want to pull a 3 or 4 horse trailer. It would probably be fine as long as everything went well...but in an emergency situation (some idiot pulls in front, avoiding a deer, etc) I'm not confident it would end well. Pulling horses is different than inanimate loads; you've got live animals back there, presumably your friends. Tipping over an inanimate load sucks, tipping over a horse trailer would be tragic. Of course there is the additional factor that live animals move around, requiring extra stability from the haul vehicle.