I decided to summarize some of the changes GM made to the Tahoe over the last 20 years. I'm quite excited to see the changes in the 2021 Tahoe. Over the last 20 years the Tahoe made a number of good changes throughout the years, and what I would consider steps backwards. 2021 seems to bring everything forwards. It seems like the engineers put a lot of thought into it. The changes are enough for me to make sure my current 02 can last at least 5 more years (or more so I can afford a used 2021). I noticed some interesting things: The official mileage does not seem to correspond to the use of AFM or DFM. The introduction of AFM with the LMG engine didn't seem make any changes to the official mileage. Even the torque increase in 2007 is not really an increase. It's just measured at 4200 rpm instead of 4000 rpm. Move forwards to 2011 when it was measured at 4000 rpm again, it went back to 335 HP. The first mileage improvement occurred with the introduction of the 6L80 transmission and improved the highway rating up to 20 and 21 mpg. The city improved to 15 mpg. The next improvement in mileage occurred in 2015 which coincided with the introduction of direct injection. I know all these mileage numbers are all hypothetical and achieved by unrealistic conditions on a test track. In reality I usually see lower than expected mileage in my vehicles because of the hilly terrain we have. It just takes one long hill to ruin any great gas mileage on a daily trip to work. I must admit I originally thought that AFM and DFM would have had a bigger effect on mileage, and perhaps is you keep it in V4 mode longer it will help. So why am I excited about the 2021 Tahoe? When you look at ergonomics, the Tahoe seemed to go backwards in my opinion. (Note, I put "in my opinion" in bold italics. I know many won't agree with me here). I use the truck to haul junk from my home to the dump, recycle station, etc. I buy materials from Home Depot. Do you know how annoying it is when you buy a 4x8 sheet of something and go to find that you are just a few inches short of being able to close the rear liftgate? So, in the 2007 redesign when they made the Tahoe longer by 5 inches, they made the cargo length shorter by 5 inches! WHY ON EARTH WOULD THEY DO THAT????? Make the truck longer, but make it less useful as a utility vehicle? Then, of course, they raise the cargo bed so that the seats can fold to make a flat cargo bed so that that when I need to haul away our broken washing machine it wouldn't fit anymore! You'd think that in 2015 things would finally get better because they increased the length of the Tahoe even more, by an entire foot to 17'10"! But, the cargo length actually decreased again, albeit an inch. Really GM! I bought my Tahoe because it would fit in my short garage. Our house was built to be compact, assuming the owners would have compact cars. I can get my current Tahoe in my garage with about 6" to spare. That means I would be able to just squeeze a 2007-2014 in my garage. Now, a 2015- won't fit. If I have to do any major work on it I won't be able to shut it in my garage overnight anymore. That was the major reason I bought a Tahoe 5 years ago, because I knew I could work on it in my garage and leave it in there locked up at night. So what does this mean about the 2021 Tahoe? It is now 18'10". No where near fitting in my garage anymore. I cannot find any specs on how long the cargo bed is up to the front seats. In wonder if they shortened it again? At least the cargo bed is no longer raised up. But I might as well get the Suburban next time. I'll admit, it looks really nice, although I really appreciate the simplicity of the cockpit of my 02. There are too many things to fiddle with for the HVAC and radio these days, but that's the common trend among all manufacturers. My next house will just have to have a longer garage.