New 2015 GMC Sierra Diesel heavy duty pick up truck offers commodity and power at the same time. This model was first time launched for 1998 model year and has a twin in Chevrolet’s Silverado model. Both Silverado and Sierra were launched to replace Chevrolet C/K pick up truck. Through all their history Sierra and Silverado were literarily the same. Although they have slightly different campaigns with Silverado being advertised as a vehicle best used for agriculture and Sierra for the industry, although it has some more luxurious trims as well.