New for 2010

GM has dropped the long-running 6.0-liter V-8 engine from the Sierra lineup, leaving the powerful 6.2-liter V-8 for heavy towing needs. The rest of the Sierra's eight-cylinder lineup benefits from increased availability of its new six-speed transmission for regular and extended cab models equipped with the 5.3-liter V-8. Also, the 4.8-liter and 5.3-liter V-8 engines have been enhanced, with variable valve timing for improved emissions and better fuel economy.

Those with portable MP3 players can connect and play their music collections with the truck's audio system through a USB connection. Standard side curtain and side-impact airbags are welcome safety additions.

    See also:

    Dinghy Towing
    Two-Wheel-Drive Vehicles Notice: If the vehicle is towed with all four wheels on the ground, the drivetrain components could be damaged. The repairs would not be covered by the vehicle warranty. D ...

    Extending Engine Run Time
    To extend the engine run time by 10 minutes, repeat Steps 1 through 3 while the engine is still running. The engine run time can only be extended if it is the first remote start since the vehicle has ...

    Customer Assistance for Text Telephone (TTY) Users (U.S. and Canada)
    To assist customers who are deaf, hard of hearing, or speech impaired and who use Text Telephones (TTYs), GMC has TTY equipment available at its Customer Assistance Center. Any TTY user can communicat ...