By the mid-1970s, Lotus sought to move upmarket with the launch of the Elite and Eclat models, four seaters aimed at prosperous buyers, with features such as optional air conditioning and optional automatic transmissions. The mid engined line continued with the Lotus Esprit, which was to prove one of the company's longest lived and most iconic models. Lotus developed its own series of four cylinder DOHC engines, the Lotus 900 series, and later a V8, and turbocharged versions of the engines appeared in the Esprit.