The new for 2020 GLB compact SUV slots between Mercedes' GLA and the GLC. The GLB is boxier than those SUVs, with a square, upright stance. Despite its compact dimensions, the GLB offers an optional, albeit tight, third-row seat. Fortunately, the 2.0-liter turbo four-cylinder powertrain is more responsive than it is in its A-Class and CLA platform mates. It posts a respectable 26 mpg overall in our tests. The GLB feels light on its feet and responsive in corners. The ride is firm, but steady and controlled. The cabin is well finished and quiet. Although the infotainment system is very capable and dazzling in appearance, we found it cumbersome to use. The GLB comes with either front- or all-wheel drive. Forward collision warning and automatic emergency braking with pedestrian detection are standard. For 2021, blind spot warning is standard.