The 2007 smart
Comprehensive Press Release
A 4.2 l/100 km car with an impressive performance value
The smart fortwo cdi – available in Europe since the end of 1999 – is still by far the most economical 4.2 l/100 km car on the overseas market. The model is equipped with what is currently the smallest common-rail diesel engine in the world. The diesel-engine-powered smart fortwo also has extensive standard equipment.
smart concept uses intelligent lightweight construction techniques
The smart fortwo cdi's strong potential for all-round savings is not only due to its frugal direct injection diesel engine, but also to its intelligent general concept. The fundamental design of the smart fortwo was conceived with low weight, low road resistance, low consumption and maintenance costs, and an impressive price-performance ratio in mind. Body panels made of plastic and a high-strength tridion safety cell made of steel demonstrate how smart was able to achieve the company’s lightweight intelligent construction, thus implementing a consistent development philosophy. The guiding principle was that cars that are particularly economical will only receive wide acceptance if the overall costs are appropriate.
The world's smallest direct-injection diesel car
The drive engineering of the smart fortwo cdi also follows the principle of "less is more": its engine is the smallest direct-injection diesel car engine in the world. This all-aluminium three-cylinder car with common-rail direct injection produces 40.2 hp (30 kW) from an engine capacity of only 0.8 litres, while its maximum torque of 74 lb-ft (100 Nm) is delivered between 1,800 and 2,800 rpm. Its maximum speed is electronically limited to 135 km/h.
Electronic exhaust-gas recirculation reduces NOx emissions
The cdi assembly, which was developed by Mercedes-Benz and is manufactured at DaimlerChrsyler's engine factory in Berlin, has an engine block made of aluminium - which very few diesel engines have had to date. Further special features include roller rocker arms weight-optimized camshafts made using the hydroforming technique and electronically regulated exhaust gas recirculation - also a new feature for the small car segment. This ensures that up to 50 percent exhaust gas is added to the inflowing fresh gas depending on the driving condition. This takes place in a mixing chamber with an electromagnetic double-plate control valve. The exhaust air that is added does not participate in the combustion and thus cools the cylinder charge and contributes to reducing the nitrogen oxide emissions, as NOx is especially likely to form when there is high excess air and so a higher combustion temperature.
High power thanks to a turbocharger with charge-air cooling
The smart fortwo cdi has a turbocharger and charge-air cooler. The maximum boost pressure of this system with its mechanical wastegate is 1.15 bar, while the maximum pressure in the combustion chamber is around 140 bar. The exhaust manifold and turbocharger housing are cast as a single component. Although variable turbine geometry was not used, the turbocharger kicks in without any turbo lag, ensuring particularly smooth power development.
High-quality equipment and state-of-the-art safety standards
The smart fortwo cdi benefits from an extensive range of standard and optional equipment, which make the car comfortable, safe and dynamic to drive. The smart fortwo represents an unrivalled, pioneering force in this segment in terms of drive technology, safety engineering and comfort. The technology offered to smart customers at no extra cost is only to be found as standard equipment in higher vehicle classes.
All models of smart fortwo are equipped with the Electronic Stability Program (ESP) as a standard feature. No other vehicle in the micro-compact segment offers this system as standard. ESP best ensures that smart cars follow the direction in which the driver steers, even at the stability limit of driving dynamics. In addition to closing the throttle valve and opening the clutch, ESP also offers brake intervention acting on individual wheels. This ensures directional stability and road adhesion when accelerating, braking and coasting. Within physical limits, ESP ensures that during fast cornering, cars do not push over the front axle (understeering) or push outwards with the rear end (oversteering). Furthermore, ESP includes additional functions which enhance the comfort and safety of the vehicle, such as Brake Assist and Acceleration Slip Control (ASR). Moreover, the Antilock Braking System ABS (including Electronic Brake-force Distribution) is integrated in ESP.
The comprehensive safety equipment of the smart fortwo also includes driver and passenger full-size air bags, belt tensioners, and belt force limiters. Long spring travel and cushioned seat backrests provide comfort to the passengers. To further increase ride comfort and active safety in the automatic mode (softouch), smart created a kickdown function which makes it possible to spontaneously change down a gear or two with the accelerator pedal.
