Totally revamped last year, the GMC Sierra is also offered in a Denali version, which has a more dazzling style, sumptuous finish and a few usual characteristics. There’s a new range of engines called EcoTec3 that includes a 4.3L 285-hp V6, as well as a 5.3L V8 and a 6.2L V8 that generate 355 and 420 horsepower, respectively. They have direct injection and variable displacement.