I found an interesting stats showing differences among different engines and towing capacity of 2017 Chevy Silverado. If we going to have the same engine options for the new 2019 model (I'm pretty sure we will), this graph works perfectly. I don't think that Chevy was aimed at the towing capabilities of their new track, so numbers shouldn't differ too much.
Aren't those the stats for petrol engines? Would it not be better to look at the Chevy Colorado's 2.8L Duramax maximum conventional trailering rating?
Good point because engine along with the type of platform its on are a couple of the major factors that determine what the towing capacity will be. Given how much more durable of a platform the Silverado is it should be safe to say we can expect a 10-15% increase in towing capacity.