1500 lb is total weight of trailer with the bikes ? That's only 50% of the rating and I wouldn't see an issue with that flat land towing. Another 1000 lbs of bikes then your pushing it in the hills IMO. What's inside the 'nox also has to be considered also, total load on drivetrain. Pulling long hills with the hammer down loaded up maintaining speed is another story, little 2.0 on high boost for a long time equals maximum stress on motor.I hope it's not towing related.
I was hoping I could tow our 1,500 pound combo trailer and motorcycles with my Equinox with the 2.0.
Max. tow rating is based on the capacity of the vehicle's brakes and gross vehicle weight plus trailer load not engine capabilities. Tahoe's can be built with several different brake packages and that determines tow rating, same with pick up's, my 16 'nox has no multiple brake packages in the RPO list, just one for either size motor .