I have the weathertech mud flaps front and rear. They make a big difference on keeping the spray down on the sides of the truck, and super easy to install. Well worth the money
I just put steps on my 2500 hd. A lot of the aftermarket were listed for 1500 as well as 25/3500. They mount to the rocker and it appears the GM kept that part the same. Factory I am told there is a difference in how low they hang below the body. Other than that those are even interchangeable
I have hand calculated mine both towing and regular driving. I have been surprised that the computer has been within .3 to .5 each time.
Towing a 35 foot 8500# bumper pull toy hauler i only average 7.5 at 65-70 range. Non towing around 16. I also only have around 1000 miles on it so I'm hoping things might improve over time.
Another option we use at work because everyone looses adapters. We wire in a separate female plug on the trailer with the 4 pin coming out of it as a male plug. this way you have to have the 7 pin male plugged in and it is protected from the elements. Little extra work but somehow that is a system they haven't broke. Had some operator error when they forget to plug the other one in but that didn't surprise us??
I think the time line depends alot on what exactly is ordered. I ordered my 2500 crew cab LT gas in mid April(during the shutdown). It arrived at the dealer mid July. I was surprised by how quick all things considered
4 months later I took deliery of my truck, 2500 LT longbed 6.6 gas. had it one day and already like it better then my 2017 1500 I traded in, can't wait to tow the camper with it