Underneath, the Silverado rides on a fully boxed high-strength steel frame with hydroforming technology; truck cab's frame is built with high strength steel as well. The third generation Silverado uses aluminum on the hood, for the engine block and for the control arms in order to save mass. The truck's bed is made of roll-formed steel instead of stamped steel used by other manufacturers in order to save weight and gain strength. The third generation Silverado introduced the upmarket High Country edition which includes saddle brown leather interior, which is Chevrolet's first entry into the luxury market. A revised front end features styling cues from the 1980s-era Chevrolet C-Series Trucks, and, on Z-71 models, a Z-71 badge was added to the front grille. The first production Silverado completed assembly on April 29, 2013. The Silverado 1500 went on sale in May 2013 as a 2014 model, with the Silverado HD Series being available in early 2014 for the 2015 model year. On January 10, 2014, a recall was issued for 370,000 Silverado and Sierra pickups due to a fire risk.