Aerodynamics, weight, intake, exhaust, tune, and gearing will all affect the power output/mileage of a powerplant used in different applications.
GM uses the LFX in a variety of cars other than the Camaro. Many make north of 300HP.
However, the Traverse is not one of them. It still uses the LLT, not the LFX that the 2012 Camaro uses.
http://gmpowertrain.com/VehicleEngin...nProducts.aspx