The second generation GMC Sierra was introduced for the 1999 model year. The second generation Sierra was built using the GMT800 platform, and was an upmarket version of the Chevrolet Silverado. This updated generation of Sierra was offered in standard cab, extended cab, and crew cab, each available with a short or long truckbed. A wide range of V8 engine options were offered, as well as one V6 option. Variants offered included the 1500, 1500HD, 2500, 2500HD, and 3500. The second generation Sierra was built until 2007, when the Third Generation GMC Sierra was introduced. Second and third generation trucks were built simultaneously in 2007, with the older generation vehicles called 'Classic.'