It's been a big year for truck debuts. Since January, we've seen the new 2019 Chevy Silverado, 2019 Ram 1500, 2019 Ford Ranger and the 2019 GMC Sierra. Just last week, we drove the new 2018 Ford F-150 Power Stroke diesel. The Silverado, Ram and Sierra HD variants will soon follow. We've even seen a teaser for the Silverado 2500. These new spy shots give us a pretty decent look at the upcoming 2020 GMC Sierra 2500 Denali.