GMC, the "professional grade" trucks of General Motors, is one of the oldest manufacturers still in existence having produced commercial vehicles since 1901. The 2007 model year saw a vast overhaul of the GMC lineup with a ground-up redesign for both the Yukon and Sierra and the company's first-ever crossover SUV, the Acadia. The industry-first, full-size hybrid SUV is the most fuel-efficient full-size SUV on the market. The Denali line, which includes the Yukon, Envoy and Sierra, caters to customers looking for luxury trucks and SUVs with potent performance and stylish looks. As with other GM vehicles, the convenience of OnStar is standard on Saturn vehicles is free for the first year.