No major changes for 2013 as we wait for a long overdue next generation. The Sierra range offers three cabs, three cargo boxes and three wheelbase lengths for a total of more than 30 different versions. Power comes from one 4.3l V6 with fourspeed automatic and three V8s, a 4.8l, a 5.3l and a 6.2l, all paired with a six-speed automatic. The Hybrid version uses the 6.0l V8 coupled to a CVT. Four-wheel drive is optional on all models except for the standard all-wheel drive Denali.