5.3L flex-fuel V-8

Two key technologies help make this Suburban a clean and relatively efficient alternative fuel vehicle: GM's Active Fuel Management cylinder deactivation allows this engine to operate on only four of it's eight cylinders under light load conditions. The onboard computer determines if /when appropriate conditions exist for cylinder shutdown, and similarly determines when reactivation should occur. Under ideal conditions as much as 12-15 percent fuel savings can be realized. Flex-fuel capability compensates for the varying ratios of ethanol in the fuel, and adjusts engine parameters accordingly. Higher amounts of alcohol produce cleaner emissions and generally, (but not always) require re-calibrated fuel delivery.