JET Thrust Stoichiometric - they're the buzz words at Alfa Romeo surrounding its volume-selling 156 sedan model.
And while they might conjure up images of a jet-powered, fire-breathing drag car, the reality is not quite so outlandish.
JTS refers to the Italian marque's new 2.0-litre engine, which replaces the 2.0-litre Twin Spark unit that has powered the 156 since it was released in Australia in early 1999.
Employing direct injection and lean burn technology to improve performance, reduce fuel consumption and lower emissions, the JTS engine represents the first of a new power unit family that will be fitted to Alfa Romeo models from now on - the JTS badge will be used to identify these models.
Alfa is claiming a world first with the JTS powerplant: the first direct-injection petrol engine with a specific power output greater than 60kW per litre and a specific torque output greater than 100Nm per litre.
Although engine capacity is unchanged, the Twin Spark's 114kW power and 187Nm torque outputs have been lifted to 121kW and 206Nm with the JTS engine - at the same time meeting the tough Euro 4 emissions standards and delivering virtually identical fuel consumption.
Of equal significance is the fact the JTS engine does not require a diet of low sulphur fuel, which has traditionally been one of the drawbacks of this type of engine technology, and is therefore able to use the unleaded petrol already on sale in Australia. Sulphur-free fuel is difficult to find even in Europe, but it is practically unknown in Australia and the US.
Alfa had to come up with an original approach to applying direct injection to petrol engines to overcome not only the fuel requirement, but also the poor high engine speed performance and exhaust gas treatment/nitrogen oxide emissions issues surrounding lean burn designs.
Alfa's solution was to configure the engine to operate as a lean burn unit at low engine speeds, up to 1500rpm, while at higher engine speeds it progressively switches to a normal fuel air mixture to provide the top-end performance expected of an Alfa Romeo.
The result is a class-leading 121kW of power at 6400rpm, as well as peak torque of 206Nm at 3500rpm, which enables the JTS to see off all of its compact prestige competitors, led by BMW's 318i and including other European models such as Audi's A4 and Peugeot's 406.
In conjunction with the release of the JTS engine, the 156 sedan has undergone a facelift with subtle exterior changes, a revised interior and a significant increase to standard equipment levels.
From the outside, only die-hard Alfisti will be able to spot the new 156 at a glance, unless you are close enough to see the small JTS badge on the rear or the new headlight washers protruding from the front bumper.
Exterior mirrors are now colour-coded, as are the rubbing strips in the front and rear bumpers, while the previous window-aerial has been replaced by a roof-mounted stub aerial and the alloy wheels now have a brighter finish.
Changes to the interior of the 156 are more substantial. The revised and re-finished dash fascia has a new, noticeably taller, centre pod that now houses an information display, as well as the two centre air vents.
The centre console has been redesigned to accommodate the new audio and ventilation system controls, and now features a "techno grey metalluro" (read: imitation metal) finish, which it shares with the steering wheel spokes, ashtray, gearshift and instrument surrounds.
The new radio/CD player is a Blaupunkt unit while the amplifier and speakers are courtesy of Bose.
Other aspects of the interior upgrade include a new design leather steering wheel and a centre console armrest incorporating a storage box.
The outgoing car's standard equipment list has been bolstered by the addition of window airbags (bringing the airbag total to six, along with dual front and front side airbags), dual zone climate control air-conditioning, cruise control, rain-sensing windscreen wipers, a multi-function display incorporating a trip computer and steering wheel-mounted audio controls.
Leather upholstery and side skirts are now also standard - they were previously part of the Monza version's specification.
The only options are metallic paint ($890) and an electric glass sunroof ($1875). Sports suspension is still available but only as a dealer-fit option.
New mechanical features include VDC (Vehicle Dynamic Control) which is permanently engaged, switchable ASR (Anti-Slip Regulation) traction control and ABS brakes with EBD (Electronic Brake force Distribution) and EBA (Emergency Brake Assist).
The proliferation of 156 models has been scaled back with the arrival of the JTS facelift. Twin Spark, Monza and Sport versions in the superseded 156 have been replaced by the single spec JTS model, available with either five-speed manual or five-speed Selespeed transmissions.
With the JTS's superior equipment levels over the outgoing Twin Spark, it now sits much closer to the previous Monza in both specification and pricing - $49,950 for the manual and $52,950 for the Selespeed, but remains more than competitive with its prestige rivals on a spec-for-dollar basis.
Alfa Romeo Australia expects to sell 550 examples of its facelifted 156 in the second half of this year, split 35/65 between manual and Selespeed. V6 sales are expected to account for between 10-15 per cent of total 156 volume.
In 2003, ARA has forecast sales of 1500 units of the 156 range, which by that stage will include a JTS-powered Sportwagon and range-topping, high performance GTA model.
* The V6 version of the 156 has also come in for some attention in conjunction with the arrival of the JTS. The 2.5-litre engine has been revised to make it cleaner and Euro 4 compatible, with power rising 1kW to 141kW and torque dropping 4Nm to 218Nm in the process.
It also picks up the other styling and equipment changes dished out to the JTS, while pricing remains at $57,500 for the manual with the Q-System automatic increasing to $59,950, a rise of $1000.
DRIVE IMPRESSIONS:
ALFA Romeo's 156 is by far the company's top-selling model, with it consistently accounting for around 50 per cent of total Alfa sales.
With that in mind, it's easy to see why the Italian marque would not want to mess too much with what has been a successful formula - the car has been instrumental in re-establishing the brand in the Australian, and many other, markets.
That reasoning goes a long way to explaining why Alfa made virtually no changes to the styling of the 156 at the time of this facelift.
A decision which may potentially frustrate those owners who are keen to update to the new model and would like to be recognised on the street for that decision, but at least it shouldn't alienate supporters of the classy design by dishing up changes for the sake of it.
In the engine department the 156 JTS certainly has changed and it now offers more performance than its Twin Spark predecessor. Not so much at the top end, where it remains exceptionally smooth and free revving, but low down where the old engine's driveability suffered from a lack of useable torque or pulling power.
It's still no grunter in the lower reaches of the rev range - it would much rather have at least 3000rpm on board to pull away quickly - but overall flexibility has improved noticeably. And the fact 156 is now more powerful than compact prestige sedan class leaders like BMW's 3 Series is welcome.
The traditional rorty Alfa exhaust note has been toned down a degree or two as a result of the engine change, but it can still be heard when giving the JTS powerplant its head.
VDC and ASR are new additions to the 156's mechanical arsenal, which is no doubt a positive for the average punter, but not totally pleasant for the keener drivers.
The 156 can be driven up to about eight-tenths without interference from either system, but it's the (switchable) ASR traction control that then becomes intrusive and, quite frankly, not particularly helpful.
It's propensity to seemingly cut, rather than progressively limit, power as understeer sets in had the effect of sending the car further off line and with the sense that the driver could do a better job on maintaining control.
The interior changes are positive for the most part, as well as ergonomically pleasing, with the exception of the cruise control stalk (but Alfa's not alone in having an awkward, fiddly cruise control system).
Ditching the wood panelling in favour of a more contemporary metal finish for the centre console, gearshift, gearshift surround and instrument surrounds has done a lot to improve the ambience of the 156's interior.
Also the chrome rotary dials for the new climate control system look sensational, while the new audio system sounds great, but is hampered by its small controls - why car manufacturers insist on trying to redesign the simple dial volume control with hard-to-use push buttons defies explanation.
But on the whole, Alfa have done a good job with the 156 facelift. Pricing has been kept under control despite the introduction of plenty of costly features and equipment, while performance has been improved without penalty at the fuel pump.
It's improved specification in the competitive compact prestige sector should see it continue to be a worthwhile alternative to its German rivals.