Introduced in late 2006 for the 2007 model year, the second-generation smart Fortwo (chassis code W451) was redesigned extensively to meet rigorous North American safety standards and enhance overall refinement. The overall vehicle length grew by approximately 200 millimeters, noticeably expanding interior shoulder room, passenger legroom, and cargo capacity behind the seats. Body styles remained a two-door coupe and a two-door cabriolet. Engine options were replaced with more durable 1.0-liter naturally aspirated and turbocharged three-cylinder petrol units engineered by Mitsubishi, generating between 61 and 84 horsepower (up to 102 hp in tuned Brabus editions), alongside an updated 0.8-liter cdi turbodiesel engine. Power delivery was managed by a newly developed five-speed automated manual transmission with significantly quicker shift times. The generation also pioneered the all-electric Fortwo Electric Drive (ED) with lithium-ion battery packs. Facelifts in 2010 and 2012 revised front styling, lighting graphics, and interior ergonomics.