3 PROBLEMS WITH MY 2011 GMC TERRAIN AWD, 2.4 LITER 1. POOR GAS MILEAGE - AVERAGING 18.8 MILES FOR A VEHICLE RATED 20 CITY, 29 HWY. I DRIVE 42 MILES DAILY, 4 CITY, 38 HWY. DEALER CHECKED, NO CODES AND STATES "OPERATING AS PER DEIGNED INTENT" 2. JERKY TRANSMISSION SHIFTS AND SEVERE HESITATION ON STARTUP AND SLOW SPEEDS IN ECO MODE. DEALER CHECKED, NO CODES AND STATES "OPERATING AS PER DEIGNED INTENT" 3. ENGINE "KNOCK" ON STARTUP THAT LAST FROM 3 TO 10 SECONDS, NORMALLY ON "COLD" STARTUP. DEALER CHECKED AND COULD NOT DUPLICATE COMPLAINT, CHECKED CAM PHASER SCREENS PER SERVICE BULLETIN AND STATES NO DEBRIS IS PRESENT. DEALER STATES NO CODES ARE PRESENT AND NOTHING THEY CAN DO. OIL AND OIL FILTER WERE CHANGED AT MY REQUEST. ENGINE KNOCK AND POOR GAS MILEAGE STILL EXIST, TRANSMISSION ISSUE SEEMS TO HAVE CHANGED TO NORMAL AND SLIGHTLY HARD SHIFTING NOW AFTER DEALER VISIT. *TR