KBB.com Brand Image Awards. Only 38,046 Miles! Scores 20 Highway MPG and 15 City MPG! This GMC Sierra 1500 delivers a Gas V8 5.3L/325 engine powering this Automatic transmission. WIRELESS CHARGING, WINDOW, POWER, REAR SLIDING WITH REAR DEFOGGER, WHITE FROST TRICOAT.*This... via HomeNet, Inc.