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Business
New Mercedes diesels
THE ANNOUNCEMENT last week that Fiat India is to launch diesel versions of its Palio and Siena ranges is a piece of good news for lovers of diesels. These cars will sport 1.9 litre, second generation common-rail engines taking them to new highs in terms of driveability and economy and a new low in polluting emissions.
The B-Class Fiats follow the more expensive C-Class Mercedes, Ford Mondeo and Skoda Octavia in this regard. The new Opel Vectra and Skoda Superb soon follow while Hyundai comes up with the much more affordable VM Motori powered Accent.
Although the Fiat Group was first with a common rail JTD engine in an Alfa Romeo, it is Peugeot and Renault in France and BMW and Mercedes (now Daimler Chrysler) in Germany that have really pushed the new technology along. The first common rail Mercedes 4 cylinder diesel was launched in the C-Class in 1997 with a whole raft of 5 and 6 cylinder engines following in 1999.
The latest E-Class Mercedes comes with an extensively overhauled range of 4, 5, and 6 cylinder diesel engines. While their displacements are unchanged, "with improved common rail injection and measures for reducing friction, these engines will occupy a leading position among competitors to the new E-Class with respect to driving pleasure, fuel economy and comfort.''
Perhaps the two most important changes effected in these second generation common rail systems is the use of seven hole injectors, instead of six, and two pilot injections, instead of one. The seven hole injectors "forced'' an increase in injection pressure to 1600 bar, but the better atomisation lead to a reduction in emissions (to the Euro 4 levels mandated only in 2005) and fuel consumption. Twin pilot injections, particularly at low loads and engine speeds, have decreased combustion noise considerably, even when compared to the already refined first generation.
Much better driveability is also a result with the torque increasing by 20 to 25 Nm at almost all engine speeds, with a particularly marked improvement at low rpm. This has been accompanied by lower production costs thanks to modular designs and no compromise with regard to the traditional Mercedes-Benz virtues of reliability and durability.
Prospective buyers of the three-pointed star would be well advised to put off their purchases until the elegant new models are available in India. This applies not only to buyers of the E-Class diesels, but also to those of the C-Class where the smallest new engine will also be available.
Those more impatient ought to consider the understated luxury of the Skoda Superb or the soon to be available Mahindra "Scorpio'' at a third the price of any new Mercedes.
C. Manmohan Reddy
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