The Expedition is still king of the hill in the full-size SUV segment.
With Ford making some dramatic (and much-needed) improvements to its full-size Expedition SUV with the 2018 redesign, General Motors was left to play catch-up, pinning their hopes on an all-new Chevrolet Tahoe and Suburban, being launched for the 2021 model year. With Ford's 2018 Expedition boasting a best-in-class max. tow rating of 9,300 pounds, and shedding weight with an aluminum body to deliver up to an EPA-estimated 19 mpg combined, the bar was set pretty high.
These numbers are claimed as "official," but so far have only been published on TFLTruck. With regard to fuel economy, the 2021 Chevrolet Tahoe is only marginally better than its predecessor, with an EPA-estimated 18 miles per gallon on the combined cycle when equipped with the 5.3L V8.
That's a 1 mpg improvement for the 4WD model, but no improvement for the 2WD - although both models do gain an extra 1 mpg on the city cycle. The story is exactly the same for the larger Chevrolet Suburban.
As for the larger 6.2L V8, combined fuel economy improves 1 mpg to 16 for the Tahoe 4WD, while the Suburban 4WD sees no measurable improvement. The 2WD Tahoe and Suburban gain nothing in combined testing, but a modest 1 mpg bump in city fuel economy.
Suffice it to say that the new, 2021 Chevrolet Tahoe and Chevrolet Suburban still can't touch the Ford Expedition when it comes to fuel economy, but it's worth mentioning that the progress in that metric comes despite the Tahoe's 5-inch increase in wheelbase and nearly a 7-inch increase in overall length.
As for towing, GM's new full-size SUVs remain outgunned by the Ford Expedition. At its peak, the 2021 Tahoe 2WD can pull up to 8,400 pounds, according to Chevy's numbers, versus up to 9,300 pounds in the Ford Expedition. Curiously, though, that's with GM's 5.3L V8 equipped; the 6.2L actually has a lower tow rating across the board. A lot goes into producing an official max. tow rating figure, but one possible explanation is that Chevrolet's SUVs are GVWR-limited in a way the Ford isn't.
But at the end of the day, if you're looking to tow more than 8,400 pounds with any regularity, you ought to be looking at a medium duty truck. Just leave the kids at home.