After being without its own in-house-developed-and-built passenger-car diesel engine stronger than 95 hp for many years, Volvo Car Corp. at last hatches a 2.4L direct-injection (DI) 5-cyl. turbocharged unit to be launched early next year.

The engine is doubly notable for having all-aluminum construction, and because its gestation period started eight years ago with the introduction of a comparable gasoline unit for the Volvo 850 in 1992.

The 5-cyl. light-alloy block was originally designed for a possible diesel version, and to date over two million gasoline variants have been built at the Skovde plant in central Sweden.

As gasoline engines, the range currently comprises three different displacements: 2.4L, 2.3L and 2L, deviating no more than 2 mm in bore from the 81.6-mm mean, with variation in stroke largely determining the capacity.

In its metamorphic form, the diesel has an 81-mm bore and 93.2-mm stroke for a displacement of exactly 2.4L (2,400 cc). Output is 163 hp at 4,000 rpm, and maximum torque 251 lb.-ft. (340 Nm) at 1,750 rpm. There are four valves per cylinder operated by DOHC, with fuel delivery by common rail to vertical injectors said to greatly minimize particulate emissions.

The new engine will be offered in the Volvo S80, V70 and S60 models. Acceleration for the fullsize S80 to 62 mph (100 km/h) is given as 9.9 seconds, with average fuel consumption a preliminary 36.7 mpg (6.4L/100 km).

Until now, Volvo filled the void in its car diesel program with a 2.5L DI 5-cyl. turbocharged unit sourced from Volkswagen AG, now fitted in the VW Caravelle and Multivan. By comparison, Volvo's new power unit is claimed to give a 16% gain in output and 17% increase in torque, knock more than one second off typical acceleration times and to halve exhaust emissions to easily beat the 2000 Euro 3 requirements. Engine weight reduction to 407 lbs. (185 kg) is another benefit.

The VW 5-cyl. turbodiesel is of course of an earlier generation, and originally appeared in the Audi 100, subsequently rebadged as the Audi A6 in 1994 and extended to the Audi A6 Avant. Output initially was 115 hp and later was uprated for Volvo to the present 140 hp. Audi has now dropped this engine entirely and replaced it with a 2.5L V-6 turbodiesel developing 150 hp at 4,000 rpm. Only VW-badged vehicles currently use the older I-5 unit, and in three versions for its commercial vehicles rated at 88, 102 and 150 hp.