Though it was originally hesitant about introducing diesel engines here, Jaguar in Australia may have got its timing just right. Upmarket European marques have smoothed the way, with German turbo-diesels now being offered in every significant market segment.

Last year we spent a fascinating two days at Jaguar's headquarters in the UK looking at and driving the new turbo-diesel models. Now we have driven the Jaguar S-Type on a full road test program in our home territory.

The diesel engine is a 2.7-litre V6 with twin turbochargers to boost its power and torque, particularly the latter. Torque peaks at 435 Nm at only 1900 rpm and the engine has a nice strong feeling in everyday driving.

Jaguar has gone to considerable trouble to make the turbo-diesel engine smooth and quiet. This includes virtually encapsulating it in a sound-deadening under-bonnet box.

The engine only sounds like a diesel when you hear it idling from the outside, and even then the typical diesel-rattle is very muted. We would defy any passenger who doesn’t know about such things to be able to pick it as a diesel from inside the cabin.

On the road the engine has some lag when you first push the throttle. That’s soon followed by a strong surge of torque as the engine begins to come on song at about 1500 rpm. It then revs willingly until the torque starts to taper off at around 4000 rpm.

The result is good acceleration for overtaking provided you anticipate for needing that extra urge. The six-speed automatic transmission certainly helps the driver, kicking down promptly by one or two gears once you give the message through the throttle.

Jaguar’s new diesel engine is fuel efficient in the manner of all modern units. Typically it will use about seven to eight litres per hundred kilometres in country driving, indeed you will be able to get it down into the sixes if you put your brain into full-economy mode. Around town the figures aren't likely to climb much over the nine to ten litres per hundred mark.

Let's pass up on the engine and get onto the rest of the latest Jaguar S-Type.

There's no doubt that this is a Jaguar from an appearance point of view. The S-Type has an almost retro look in some areas, yet is thoroughly modern in others.

The 2004 facelift of the S-Type saw the front end being simplified to a purposeful, almost stark, layout. The radiator grille has a strong shape and the aluminium bonnet on all versions of the car has even bolder sculpting than previously.

Inside the cabin is where all Jaguars really excel. There you find the traditional Jaguar-style gentleman’s club ambience that the British do oh-so well. There's liberal use of leather and woodgrain and those who love the good things in life will be very impressed.

The interior is on the tight side, admittedly a Jaguar trademark for generations and a feature you find in many other sports sedans. Couples on their own, or those with pre-teen children will find it works nicely.

Boot space is good and the mid-sized Jag is generally easy to load, though bulky items may cause you hassles at times.

Handling may be considered soft by hard drivers, though those who like to be cosseted in comfort will find it just right.

There's some feeling of understeer created by the extra weight of the diesel engine, but you really have to concentrate to notice it. On the whole the car is nicely balanced for general use.

As a high-speed cruising machine the Jaguar S-Type turbo-diesel works brilliantly, being able to put away the miles with contemptuous ease. This has long been a forte of Jaguar and the diesel adds a new dimension in efficient running.

Last year Jaguar was hesitant about also importing its topline model, the XJ series, with a diesel powerplant. But the upsurge of interest in diesels means it’s definitely planning to introduce the car here, probably in June or July 2007, though final details are still to be decided. We have also driven the Jaguar XJ turbo diesel in England. Because it’s an all-aluminium car, and therefore lighter than the S-Type, it feels significantly livelier.
 
AT A GLANCE

MODEL RANGE
S-Type SE 3.0-litre four-door sedan - $89,990
S-Type Luxury 3.0-litre four-door sedan - $99,990
S-Type Diesel Luxury 2.7-litre four-door sedan - $101,490
S-Type Luxury 4.2-litre four-door sedan - $124,990
S-Type R 4.2-litre four-door sedan - $169,990

FEATURES
ABS Brakes: Standard in all models
Air Conditioning: Standard in all models
Automatic Transmission: Standard in all models
CD Player: Standard in all models
Central Locking: Standard in all models
Cruise Control: Standard in all models
Driver Airbag: Standard in all models
Passenger Airbag: Standard in all models
Front Side Airbags: Standard in all models

SPECIFICATIONS (Jaguar S-Type Diesel 2.7-litre four-door sedan)

ENGINE:
Capacity: 2.720 litres
Configuration: Longitudinal V6
Head Design: DOHC, four valves per cylinder
Compression Ratio: 17.3:1
Bore/Stroke: 81.0 x 88.0mm
Maximum Power: 153kW @ 4000rpm
Maximum Torque: 435Nm @ 1900rpm

DRIVELINE:
Driven Wheels: Rear
Manual Transmission: Not offered
Automatic Transmission: Six-speed
Final Drive Ratio: 3.07:1

DIMENSIONS, WEIGHT AND CAPACITIES:
Length: 4905mm
Wheelbase: 2909mm
Width: 2060mm
Height: 1447mm
Turning Circle: 11.5 metres
Kerb Mass: 1790kg
Fuel Tank Capacity: 68 litres
Towing Ability: 750kg (1850kg with braked trailer)

SUSPENSION AND BRAKES:
Front Suspension: Independent, double wishbone, anti-roll bar
Rear Suspension: Independent, double wishbone, anti-roll bar
Front Brakes: Ventilated disc
Rear Brakes: Ventilated disc

PERFORMANCE:
0-100 km/h Acceleration: 8.6 secs
Standing 400 Metres: 16.6 secs

FUEL CONSUMPTION:
Fuel Type: Diesel
Fuel Consumption - Combined Cycle (ADR 81/01): 7.8 L/100km

STANDARD WARRANTY:
Three years/unlimited km