Thursday, January 14, 2010

Volkswagen's 1.4 TSI tested: Best of both world (of forced induction) ?


In this age of downsizing, lowering emissions, minimising fuel consumption and a varieties of hybrid plus concept alternative electric/fuel cell powertrains, the engine that you see above is a current production marvel considering its diminutive size but high output, yet delivers decent kilometres to the litre. Being awarded "International Engine of the Year" in 2007, this is a rare powerplant that enjoys both supercharging AND turbocharging, all in one compact package. So does it drive better than a single turbo/supercharger, twin-turbo or a twin-scroll turbo or perhaps a variable geometry turbo? The answer was a resounding yes...for the first 15 minutes or so as you get newly acquainted with the powertrain - undoubtedly, VW's DSG is very much still excellent - but not unlike getting a new girlfriend, the relationship gets a wee bit too revealing (no pun intended) and jaded as you peel the onion by the layers...



Externally, the Jetta is beginning to show its age. It has a very clinical design that apes the big brother Passat (non-CC version mind you) which doesn't look very awe-inspiring when downsized to C-segment dimensions. The all-new replacement model is already on its way, due sometime 2011.

But we're not here to dissect the Jetta's aesthetic exuberance or the lack of it. Though just rated with a maximum output of 140bhp, this Jetta felt noticeably livelier than the Jetta 2.0 FSI that I tested some years ago for TopGear Malaysia mag, if my memory serves me correct. As that 2.0 FSI had a usual torque converter which makes it less superb by default, drivetrain wise at the very least.




Internally, the Mk5 Golf interior could not be faulted, built and ergonomic wise, though a tad too much grey tend to make it a bit of a drab to be in for longer drives. The light shade, off-white headliner and top trim saves the day, thank goodness for that. With the meters in blue, once-glance legibility can still be an issue for at night since our eyes' retina cells aren't very much sensitive to blue being the colour for fine details, which in this case are the speedo & tachometer fonts and gradation scales. A simple white-on-black will do better.




Noise insulation will be top-notch for a car this class and size if not for the drumming road noise/tyre roars on harder tarmac sections of highway. Note to what extent VW chose to line the doors of their 'budget' sedan, it looks like they have no budget constraint even for a global volume seller like this Jetta.



I have also never seen such big door pockets for a sedan of this size. Mercedes-Benz, you've got a thing or two to learn from VW here. Porsche too - maybe this is more ammendable in the near future since Porsche is part of the ever expanding VW-Audi group now. The seats are also one of the best in business for snug bolstering and support, even though I found myself craving for a harder back-board on many occasions, for a more insulated ride from hyperactive kids knees-nudging into your seat from the back. That's just as irritating as hormones-raged adolescents kicking your chairs in a crowded cineplex.








With a humongous boot that both deep and wide, the Jetta has no luggage issues for all 5 occupants driving off to some secluded resort for a long weekend getaway. Makes for a great family sedan, without a doubt. Towards this goal, the suspension setting is more comfort-biased (read: soft) as well. Undeniably, the MK5 Golf chassis has excellent tracking around corners with the rear axle geometry very faithful to where the front wheels are turning.




Driving the 1.4 TSI can be a chore during the initial take-off since the compressor wheel of its supercharger very much taps off the crank. Much like taking one-step-back-before-two-steps-forward, the Jetta is eerily like a Mercedes E200K in low-end drive response. There's a little lack of grunt below 2,000 rpm. However the force-fed punch gets very real and palpable - along with quick succession of upshifts by the intelligent and responsive DSG 'box - as you climb quickly beyond 2000rpm.

Strangely too, the was a flat spot circa 120km/h where you'd find the power tapering off only to recover with a second tsunami wave by 150km/h or so, with nicely welcomed 'whoosh' of a punch, enabling cruising on a stretch of open, private roads a true joy. Perhaps the ECU mapping for this 140hp does not unleash the full, manic potential of this 1.4 TSI lump, which is 170bhp in the Golf GT. Fuel consumed for the Jetta 1.4 TSI over a 3-day period was RM100 or 48.78l for 425km, which worked out to be about 8.7km/l. I found myself pushing hard more than 50% of the times, working the engine mostly to its redline limit. I have also used RON 97 petrol in the hope of maximising forced-induced output even though VW claimed that a minimum RON95 is sufficient dietary requirements, even for their high-tech, more complex twincharged engine.





Looking very much like Golf R32 (or Golf GT?) in the mid-section of VW's typical goateed grille, the Jetta 1.4 TSI does command a little respect on the road should you decide to hurry things up with intentions to pass traffic ahead of you. Sadly, the mid range flexibility form say 110 km/h -140km/h was sorely lacking in this TSI lump. It makes me curious if a simple twin scroll turbocharger would be better and perhaps, more cost-effective in execution. Keep the excellent duo of direct injection and DSG. In the meantime, I'd take the 2.0 TSI in Golf GTI Mk6 anytime over this for better mid-range flexibility and higher top-end whack. Even my wife's single turboed Colt Ralliart has more linear punch and powertrain flexibility. That's my take for this 140bhp TSI twincharged marvel from Volkswagen. Sorry, this doesn't get my vote for green, lean and mean choice of purchase.






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