To me this is a bit of a head scratcher. Towing a high profile enclosed trailer of similar weight with a 6.0 powered 2500HD Chevy I would get 12. Towing a longer, heavier (3300 pounds) high sided travel trailer with an old Ford Aerostar I'd get about 12-13, and my Aerostar had barely half the power of the current 4.3. To say that that engine is working hard with that small load is just ignorance. 285 hp/305 torque is better than small block V8s of not many years ago, and with direct injection and variable valve timing the torque curve should be nice and flat.