Ride along with John Ambrozic from Smail GMC as he gives an in-depth look at the new 2020 GMC Sierra 2500HD AT4

This heavy duty truck boasts a DuraMax 6.6L Turbo-Diesel V8 engine paired with a new 10-speed transmission.

For full details on this truck and more, visit https://www.smailbuickgmc.com/Vehicle...