get in and out, which is useful for those with personal mobility problems, such as the elderly and the disabled. The conflicting design goals for economy cars – small size with maximum usable interior space, low cost and light weight with acceptable safety performance (light cars have a higher ratio of unsprung suspension mass to sprung mass, which affects ride quality) and the need for light materials with acceptable durability – continue to stimulate innovative development. Technology improvements such as electronic engine management, adoption of four valves per cylinder, variable valve timing, direct injection of petrol/Gasoline and diesel, hybrid power, and smoother, more powerful diesel engines with very high pressure electronic injection, have dramatically improved fuel economy and performance. The latest technologies to improve efficiency are engine downsizing and automatic engine stop-start. Automatic engine stop-start systems like VWs BlueMotion, shut the engine down when the car is stopped to reduce idling emissions and boost economy, and it is now mandatory not to idle unnecessarily in cities in Germany. It is an updated version of the 1980s VW 'Formel E' system that was developed into the 1990s VW 'Ecomatic' system. The application of turbo-charging to downsized engines is one way to achieve efficiency benefits into fuel economy and emission benefits instead of for performance. The recent Fiat 'Multiair' system, is an electro-hydraulic development of variable valve timing that allows the engine management computer to control valve timing, improving engine efficiency, giving better torque, power, economy, and emissions. Safety design is a particular challenge in a small, lightweight car. This is an area where Renault has been particularly successful. Sport compacts and hot hatches have developed into their own competitive genre. Although their economy has been compromised, these models offer higher performance because of the lightness of the platforms that they are based upon. As an alternative to manual synchromesh gearboxes, automatic continuously variable transmission (CVT) gearboxes are optional on some economy cars, such as Audi, Honda, and the MINI ONE and MINI Cooper. Tata Motors from India, recently announced that it too would use a variomatic transmission in its Nano. CVT application to economy cars was pioneered by Fiat, Ford, and Van Doorne in the 1980s. Rather than the pulled rubber drive belts as used in the past by DAF, the modern transmission is made much more durable by the use of electronic control and steel link belts pushed by their