2017 to 2020 GMC???????

I have a few questions
Looking at possible going back to a Gas burner. Looking at used 2017 up. What should I know about these GMC Sierra's 1500's?
What kind of MPG do you get with one.?
I have not owned a Gas Burner since 1989. Always a Dodge Cummins, 1990, 1994, 1998, 2003, and now 2012 1/2. Just do not tow heavy like I use too.
All help appreciated
Thanks.

New half ton will ride much better than an older 3/4 or 1 ton. Gas mileage isn't gonna be great. Towing mpg will be really bad. Towing power will be nonexistent compared to any HD diesel. But no emissions equipment and lower purchase price and lower maintenance costs.

I have a 2019 GMC Sierra 1500 4wd Denali 5.3L. Tows my BassCat just fine, averages 20 mpg (hand calculated) around 14 mpg towing. Have 37K miles and zero issues so far. They are noted for having lifter issues with the cylinder deactivation system and some folks have problems with the 8 speed transmissions.

I had a 2004 5.3L with the 4-speed auto and never had an issue - sold it with 160k miles. But I have 2 buddies with the cylinder deactivation and both have had issues - one major and one minor. Personally I wouldn't buy a new model motor.

My friend too, with the lifter thing.

When did they go to the cylinder deactivation system and the 8 speed?

I got a 2020 Z71 Chevy 5.3 with a 8 speed .Gets 21 and highway and 18 in town , i pull a 20 ft boat with no problem , i have 8500 miles on it ,

Cylinder deactivation was 2007 I think. The 6-speed was before that. I don't know when they went to the 8-speed, but the 6-speed wasn't great either. When I was shopping transmission shops for my wife's last car that had transmission problems, the shop said, "See they price these transmissions based on supply and demand. The Highlander transmission your wife has hardly ever breaks down so they don't make many replacements and the price is high. The 6-speed GM truck transmission however is one of the most unreliable and lots of manufacturers make rebuild replacements and prices are pretty low." I was a bit shocked.

Personally I'd consider the new Ram. I had two half tons and both did well on mpg, the Hemi motor is fantastic, the truck itself is more comfortable and has better creature comfort layout, and Ram's ZF 8-speed is nearly bulletproof. We had several guys on my last forum with a half million miles, nearly all towing stuff that's often too heavy for a half ton, and zero transmission issues

$600 and a little time and you can install a DOD delete. Get a 6.2.