The Hummer H3 receives a few minor updates for 2010. The 5.3-liter V8 engine, which powers the high-end H3 Alpha trim, gains FlexFuel capability for 2010, enabling it to run on E85 fuel, a blend of 85 percent ethanol and 15 percent gasoline. An optional appearance package now includes 16-inch chrome wheels and other chrome body enhancements. In addition, Hummer offers the H3 in three new colors for 2010, including Red Rock Metallic, Silver Stone Metallic, and Canyon Metallic. The four-door Hummer H3 midsize SUV comes in four trims for 2010, including the Base H3, the H3 Adventure, the H3 Luxury, and the H3 Alpha. A 3.7-liter inline five-cylinder engine, generating 239 horsepower and 241 pound-feet of torque, powers all trims except the Alpha. In the Base H3 and H3 Adventure trims, the five-cylinder links to a five-speed automatic transmission, while the H3 Luxury trim receives a Hydra-Matic four-speed automatic transmission. The H3 Alpha's big V8, which produces 300 hp and 320 lb-ft of torque, also mates to the four-speed automatic. All five-cylinder models boast a towing capacity of 3,000 pounds with the manual transmission and 4,500 pounds with the automatic. The H3 Alpha can tow up to 6,000 pounds, living up to its name as the alpha dog of the pack. As their names imply, each H3 trim addresses a different type of owner. The H3 Adventure, for instance, comes equipped with an Off-Road Suspension Package, which includes front and rear fully locking electronic differentials, a 4.03:1 two-speed transfer case, and beefy 16-inch all-terrain tires, all designed to handle rugged off-roading. The Luxury trim includes leather upholstery, heated eight-way power-adjustable front seats with lumbar support, and a leather-wrapped steering wheel. The Alpha trim, designed for high performance as well as upscale comfort, also offers leather seating, heated power-adjustable front seats, and a leather-wrapped steering wheel in addition to its V8 engine. Standard features for all trims include Bluetooth wireless technology, cruise control, power windows and door locks, a Driver Information Center, air conditioning, a 60/40-split fold-down rear seat, and an electrochromic rear-view mirror with a compass, outside temperature display, and OnStar controls. The Base H3 comes with an AM/FM audio system with a CD player, while the other trims upgrade to an in-dash 6-CD changer. XM satellite radio comes standard on all trims, while features such as navigation (via an upgraded OnStar system) and a rear-view camera system remain options for all trims. Safety and performance-related features for all 2010 H3 trims include GM's StabiliTrak electronic stability system, power-assisted rack-and-pinion steering, traction control, four-wheel antilock brakes, and full-time four-wheel drive. All trims also come equipped with foglights, power-adjustable exterior mirrors, halogen headlights, and a one-piece rear swing gate. Dual front airbags and head curtain side-impact airbags with a rollover sensing system also come standard on the H3.