Tech Briefs
October 2003
Jaguar's diesel arrives
It has taken a very long time to become reality, but Jaguar is now a member of the diesel club. In Europe, having both diesel and gasoline engines across the range—from small, low-price models to high-level executive cars—has become essential for success, particularly as diesel technology has made enormous strides in terms of performance, driveability, low noise, and economy. Jaguar's first step into the diesel world is with the X-Type, using Ford's TDCi 2.0-L four-cylinder, 16-valve turbodiesel with common-rail injection, already powering the Mondeo. The 128-hp (95-kW) engine produces 330 N•m (243 lb•ft) from 1800 rpm with a brief overboost availability to 350 N•m (258 lb•ft). CO2 emissions are 149 g/km (240 g/mi) with fuel economy of 5.6 L/100 km (42 mpg) for the combined cycle. The Ford unit was the right mass—195 kg (430 lb)—and size [length 500 mm (20 in), width 610 mm (24 in), height 680 mm (27 in) including the flywheel and clutch assembly] for Jaguar's needs. The engine has a cast-iron block and aluminum ladder frame. It has an aluminum alloy cylinder head with separate aluminum alloy camshaft carrier assembly. A duplex chain drives twin overhead camshafts. The engine uses common-rail direct injection with variable geometry turbocharger and a charge-air intercooler. Injection pressure ranges from 230 bar (3.3 ksi) at low engine speed to 1500 bar (21.8 ksi) above 2000 rpm. The engine has a combustion noise sensor that "listens" to each stroke in individual cylinders and can adjust pilot and main injectors every 0.3 ms. The system, which has a learning capability, calculates the minimum drive pulse needed to provide the required output with the lowest combustion noise, notably at idle. The learning aspect means that the engine should become quieter in service than when new.
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