At first you will confuse the new GMC Sierra series with the 2015 Chevrolet Silverado 2500/3500HD! However, GMC seem to be placing the whole game a notch higher with the 2016 GMC Denali 3500HD. The new LED lighting plus its masculine body give it a new and refined look. 2016 Denali is specially built to allow air circulation in the engine compartment and inside the car.