If you need to move large cargo or large numbers of people from A to B, look no further than GM’s largest SUVs. At 224 inches long, the Suburban and Yukon XL are some of the biggest passenger vehicles sold in America. For 2016 GM has tweaked the top-end Denali trim with a new transmission that brings improved fuel economy, better towing and improved performance. The price tag? That’s still a little steep.