ARLINGTON (CBSDFW.COM/CNN) – It looks like workers in Arlington will be busy for a long time. General Motors has unveiled all-new versions of the Chevrolet Tahoe and Suburban.

The biggest changes make the two popular large SUVs even longer and roomier than before.

READ MORE: Shoppers Back In Stores This Black Friday, But Shopping Season Kicked Off Weeks Ago

The big SUVs are important to the automaker’s profits. The Tahoe and Suburban account for more than 40% of America’s non-luxury full-size SUV market, according to data from Kelly Blue Book.

The Suburban is identical to the Tahoe except that it’s always been longer. That’s still true in these new versions, but they are now closer in size. The 2021 Tahoe is 6.7 inches longer than the current one. The new Suburban is 1.3 inches longer than the Suburban’s now on sale. Both also have longer wheelbases.

Thanks, in part, to that extra length, these new SUVs have more cargo space and 10 inches more legroom for passengers in the third row seats, according to GM. The new Tahoe, for example, has 66% more cargo space behind the seats.

The new 2021 Chevrolet Tahoe is revealed by General Motors on December 10, 2019 in Detroit, Michigan. (credit: Bill Pugliano/Getty Images)

READ MORE: 16 Units Damaged In 3-Alarm Apartment Fire In Fort Worth

The new SUVs also have independent rear suspension that should improve handling and ride quality. Until now, these large SUVs have had solid rear axles. That’s similar to the rear suspension of GM’s pickup trucks.

The Tahoe and Suburban will be available with either of two V8 gasoline engines, one producing up to 355 horsepower or a larger one producing up to 420. A six-cylinder diesel engine is also available, the first time a diesel has been offered in these models. To save fuel, the V8 engines can shut off anywhere from one to seven cylinders when full power isn’t needed. The engine can also shut off automatically when the vehicle stops, then restarts as soon as the brake pedal is released. GM has not released fuel economy ratings for these vehicles yet.

GM officials say the new Tahoe and Suburban will go on sale in the middle of 2020. Pricing hasn’t been announced yet but the Tahoes and Suburbans at dealerships now start at around $50,000.

The General Motors Assembly plant in Arlington is the automaker’s sole producer of full-size SUVs – including the Chevrolet Tahoe and Suburban, GMC Yukon, and Cadillac Escalade.

MORE NEWS: Frisco Firefighters Extinguish Kitchen Fire, Save Home From Blaze

(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The-CNN-Wire™ & © 2019 Cable News Network, Inc., a Time Warner Company contributed to this report.)