mdreynolds

I've had the 10 speed in my 2020 Sierra AT4 and my 2021 Silverado Trail Boss, both have been probably the best shifting trannies I've ever owned, Before purchase of both I verified they were 10 speeds, because the 8 has been troublesome since day 1, supposedly the 8 speed has been updated in several ways when it gets to the 2023 Colorado and Canyon, but time will tell, stick with the 10.

I worked as auto tech at car dealers for 12 years, we had a brand new Hyundai that had a noise under the seat, after stripping the seat and carpet, still something rolling around under where the seat is mounted, ended up cutting a hole in a enclosed brace/gusset under the seats, someone at the factory put a steel pinball in there before it was welded up, Hyundai had to buy the car back because we had to cut a structural part of the car out to find the noise and remove it. Funny stuff right there.

There's a intake sound/growl that larger displacement makes, especially back when you could turn the air filter lid upside down to hear the engine sing, my past 4.8 and 5.3 trucks didn't have it, but if you grew up around big ole engines you would know about it, now its time to get a CAI to get the full effect (Like turning the lid upside down), but you may not be old enough to remember that.

2020 AT4

My 2020 AT4 doesn't have them, I'm sure its a Chevy GMC thing, different hood shapes, different aerodynamics, they tweak the smallest things for airflow.

I purchased a 2020 Sierra AT4 with the 6.2 the fell in the date range of the valve spring issue, I have 6K miles, and I drive it hard, no issues with the entire truck, the valve spring didn't affect a large percentage of the 6.2s produced from June 1, 2020 thru Sep 15, 2020, valve spring were manufactured by an outside vendor, the problem was identified and corrected, so purchasing any 2021s or really late 2020s produced after Sep 15, the issue has been rectified, you'll be good, some people think its a widespread issue, but only affected a small portion of the 6.2 produced during that period. BTW I LOVE that engine, its badass and get decent MPGs if driven lightly, Im averaging 15.9 after 6K, that lots of idling, off roading and city driving, the best 50 mile trip was 23.5, best 400 17.6, again that 400 includes a lot of the mentioned conditions.

Agreed, After driving Sierras and Siverados with the 2.7s, 3.0Ds, 5.3sand 6.2s, I needed up with the 6.2 AT4, the 2.7 seemed to be trying to hard, 3.0 was great, but a first year engine, 5.3 throttle response was lacking, but the 6.2 was my first vehicle to bring back the warm and fuzzies I got from my first car, 1975 Dodge Charger with a 360, that sound, that power, and on a recent 2000 mile trip, i had 400 stretch avg. 19.6 mpg, keep in mind that 15.9 overall was 50 to 75 photo stops, hours of creeping along mountain ridge trails in Colorado and lots of idling. Only regret is possibly the 3.0 Diesel, give it a couple years on the market and i may go that direction.

OK, the 2021 Yukon has arrived, The AT4 version was tested, And i noticed the front skid plate is aluminum, in the same spot where Sierra and Siverados have the plastic splash shields, between front bumper and front crossmember. So the new Yukon/Tahos are based on the current truck platform, aside from the rear independent suspension. I wonder if the aluminum skid plate would fit the trucks, in place of the plastic splash shield, that's a place i always though where aluminum would be needed. Any thoughts.

Had it Colorado this last week, didn't take any pics with extreme flexing, but we spent several hours driving on mountain side trails, also confirmed you can hit 115mph, about 112mph the top speed cutoff starts kicking in, with momentum getting to the 115 mark. 1945 miles over 7 days, 5+ hours of trails, 50+ photo stops, hours of idling, lots of side road and highway driving i ended up at 17.6 mpg with the 6.2, quite happy with that.

Same here, (2020 GMC AT4), it has nothing to do with the LCD not displaying black, although not "True" black like you get from OLED. But look at the stock OEM NAV, it has dark blacks, but the CarPlay contrast or brightness is way off, looking washed out, my 2016 Silverado Car Play displayed dark blacks and vivid colors, same with my wife's 2019 Honda, dark blacks and vivid colors using Car Play, All using the same phone and cable, I wonder if GM wants you to purchase the OnStar package so NAV will show up better than Car Play. It's really frustrating.

The 49K is one with the Premium Pkg, $3000 and upgraded tires $495, The one I purchased for 52K included the Premium Pkg, $3000, 6.2 V8, $2495 and 20" wheels, $895. Premium Package = -Front and Rear Park assist -Lane Change Alert -Side Blind Zone Alert -Wireless Charging -Black Running Boards -Bose Sound System -Premium Infotainment with Nav -Power Sliding rear Window -Universal Home Remote

Had the "Sierra" badge and the dealer logo removed before it was polished and the ceramic coating on the paint, no more Sierra on the truck, people ask what a AT4 is.

I fit with 3" roof clearance (Shark Fin) and 4' to spare in length. Radio antenna does hit, but that's no biggie.

In Tulsa you can pick up a new AT4 with premium package for 49K, has 95% of what Denali has but with a 2" lift.

Picked up my new AT4 yesterday day, Same color but with a 6.2.