Free Racing Games-http://racinggameshq.com/

Play free racing games, new games added frequently. RacingGamesHQ.com is a site featuring only the most fun racing games, including bike, car, truck, and driving racing games. All are free and playable in any browser.

Truck games-http://www.flashgamesnexus.com/flash-games-category/Truck-Games.php

Dozens of free online games feature big trucks and monsters trucks