Renault has committed to selling by 2008 one million vehicles emitting less than 140 g/km of CO₂, of which one-third emit less than 120 g/km. The Renault eco² signature backs up this pledge by proposing a range of economical cars consuming less than 5.3 l/100 km, for diesels, and less than 5.9 l/100, for gasoline models.

Some Renault eco² vehicles run on biofuels, which help to reduce CO₂ emissions by 20% to 70% depending on the biological matter used. Renault plans to boost its offer by 2009, with 100% of its diesels able to run on biofuel and 50% of its gasoline powerplants able to run on a gasoline/ethanol blend.

Less CO₂ also means lower fuel consumption. Through enhanced aerodynamics, reduced friction and lighter-weight components, Renault engineers are focusing on the development of efficient and economical vehicles.

Renault is also focusing on downsizing, reducing engine capacity with no loss in performance by using turbochargers. The TCe 100 engine has the torque of a 1.6, the power of a 1.4 and the capacity of a 1.2. Clio models powered by this unit consume 30% less fuel than first-generation models.