C T SENGINEFuelYour CTS is equipped with a 17.5-gallon fuel tank. When approximatelytwo gallons are remaining in thetank, a low fuel warning light willilluminate in the Driver InformationCenter.The fuel door is located on the rightside of the vehicle and can beopened by pressing the forwardedge of the door with your fingers.Coolant Heater (if equipped)The engine coolant heater can makestarting the engine easier attemperatures below 0°F (-18°C).For best results, the coolant heatershould be plugged in at least fourhours before starting your vehicle.TRANSMISSIONAutomatic OverdriveAutomatic Overdrive is best used fornormal driving. To activate passinggear when going less than 35 mph(56 km/h), push the acceleratorabout halfway down; when doingmore than 35 mph (56 km/h), pushthe accelerator all the way down. Forfurther information regarding gearselection for various drivingconditions, refer to your OwnerManual.Driver Shift Control (automatictransmission only)The Driver Shift Control (DSC) modeallows you to change gears similar toa manual transmission. To use theDSC mode:1. Slide thegearshift leverfrom AutomaticOverdrive (D)to the right intoDSC.2. Press the gearshift lever forward toupshift or rearward to downshift.Activation of the DSC mode isindicated by the illuminated sportmode light on the instrument panelcluster. Also, the odometer willchange from the mileage to anumber indicating therequested gear range.When in DSC mode, ifyou do not move thegearshift lever forwardor rearward to shift,the transmission willbe in sport mode andwill still shiftautomatically.The transmission will only allowshifting into gears appropriate for thevehicle speed and engine rpm. Thetransmission will not automaticallyshift to the next higher gear if therpm is too high.Powertrain & MaintenanceNote: The grade of gasoline you use canaffect the performance of your vehicle andmay even cause damage. Please refer toyour Owner Manual for completeinformation regarding suggested octaneratings for optimum performance.