The Buick LaCrosse comes in three models: The base CX and the more luxurious CXL are powered by Buick's veteran 3.8-liter overhead-valve V6, rated at 200 horsepower. The performance-oriented CXS comes instead with a 3.6-liter V6 with modern double overhead camshafts and variable valve timing; although slightly smaller in displacement, it develops 240 horsepower. Safety features on all models include anti-lock brakes (ABS), traction control, a tire-pressure monitor, and side-curtain airbags, along with the required front airbags. Optional safety features include park assist and StabiliTrak electronic stability control.For 2007, Buick LaCrosse benefits from revised trim and equipment upgrades, including a standard tire-pressure monitor and available Turn-by-Turn navigation from OnStar. Otherwise, it's largely unchanged from 2006.