2021 Gmc Sierra 1500 Carbon Pro Cargo Capacity, Transmission Changes – Using the new age group of the pickup truck out for 2021 year, the 2021 GMC Sierra 1500 is certainly not taking lots of changes. The forthcoming model may not have as many choices as we might like, consequently this might be a section where by the vehicle could increase. Additional features and potentially more trim amounts are usually all we are able to get from this 2021 model.