On test
Škoda Fabia Greenline

Škoda’s supermini has always been a popular car. Since the original Fabia was launched a decade ago, roughly one and a half million of them have been sold around the world. There’s no doubt that the little hatchback has done a lot to deserve its following: Škoda has more than enough nous to take what’s on offer from Volkswagen — floorpans, drivetrains, running gear and assorted componentry — and to make something that is uniquely its own. The Fabia I earned a reputation for comfort and roominess, good NCAP safety results and a certain knockabout toughness.

While the Fabia’s smaller petrol engines were unremarkable, and a rather heavyweight build made them struggle, Volkswagen’s unit-injector TDI units turned it into a very grown-up car. With effortless torque and long gearing, the four-cylinder 1896cc TDI 100 in particular delivered fine performance and economy. Ride quality and open-road refinement were excellent for a small car.

A three-cylinder version of the same engine was offered: literally three-quarters of a TDI 100, it delivered 75PS.

You could also buy a Fabia with the 130PS TDI motor: with (quite rightly) lowered and stiffened suspension, a dual-mass flywheel to damp vibration, a six-speed gearbox and various bodywork alterations, the VRS delivered vast torque and almost laughable mid-range acceleration.

Early Škoda Fabia VRS. This model used a 130PS TDI engine with six-speed gearbox. Photo copyright © Škoda Auto a.s.

When Škoda launched the Fabia II three years ago, it came fitted with revised TDI power-plants. Cleaner and more powerful, the 100 was now a 105 and the 75 became an 80. The high-pressure unit-injector system remained, delivering fuel into the cylinders at well over 2000 bar.

The unit-injector engines’ weakness — so far as the driver and passengers are concerned — is refinement. They’re uncouth and rather vibratory power-units in urban driving, and their voice does not subside into the background until you’re out on the open road. For this reason, the Fabia TDIs have always been something of a paradox: small cars that grudgingly put up with town driving, but are much more in their element on the open road, where they are effortlessly competent and a pleasure to drive.

Škoda Fabia Greenline: lower ride-height, truncated bumper moulding, alloy wheels, aerodynamic panelling underneath and badging are external differences from standard car.

In this test, we are looking at the last of the unit-injector Fabias: the TDI 80 Greenline. Volkswagen has not only replaced the unit-injector engine family, but it has abandoned unit injector technology. Now, along with all other manufaturers, Volkswagen has committed itself to using common-rail designs.

It’s hard for a common-rail system to approach the injection pressures — and thus dispersion power — of a unit injector engine. But the injection pressures of common-rail systems are increasing, and common-rail has a critical advantage over unit-injectors: injection pulses are initiated electrically and controlled electronically; they can be very short, and their timing is infinitely variable. Up to (currently) eight separate injection pulses can be delivered, allowing fine control of the combustion process and the rate at which the temperature and pressure of the cylinder rise.

In a couple of months we will be bringing you a road-test of the new generation of Fabia TDI, with a 105PS common-rail engine and the same CO2 emissions as the Greenline, despite deploying an extra 25PS. In the mean time, we’re taking a last look at one of the great small car engines of the last 20 years — and a technology that is effectively now relegated to history.

The Fabia Greenline is a heavily modified version of the standard 80PS TDI model, although the old three-cylinder unit-injector engine itself is unchanged. The exhaust system is fitted with a particulate filter; to reduce the frontal area, the ride-height is 15mm lower than normal, the front bumper is shallower and unfashionably narrow 165/70R14 tyres are fitted; and — critically — gear ratios have been substantially altered. The engineers at Mladá Boleslav have taken a lot of trouble to wring the best possible fuel-efficiency out of the Fabia TDI 80. Has it been worth it?

Performance & economy

Volkswagen’s three-cylinder TDI delivers its maximum torque of 195Nm at 2200rpm. This is interesting, because the four-pot version peaks at 1800rpm, and they have the same internal architecture. Could it be that the 1.4-litre engine uses the same (comparatively large) turbocharger as the 1.9? We haven’t been able to verify this, but it would explain why the smaller power-unit takes a while longer to get the blower spinning.

In use, the three-cylinder engine feels a lot less progressive in its power delivery than its larger relative. In the Greenline, the effects of the engine’s peakiness are amplified by the car’s gear ratios, which are very widely spaced.

There is little torque below 1500rpm; in fact, a glance at the trip computer confirms that fuel consumption starts to rise sharply below this speed, even under light loads. In gentle suburban running, 1700rpm or so will provide prompt responses to the accelerator, though there is still little real torque available. From 1800rpm upwards, though, the supply of torque starts to increase sharply, and from 2000rpm the Greenline takes off with great energy.

It is this combination of poor low-speed torque and widely-spaced gear ratios that defines the Greenline in town, turning an agreeable car — which the standard TDI 80 certainly is — into a rather frustrating beast. The gap between second and third gears is particularly aggravating: changing up from second at, say, 2700rpm will land you at under 1700rpm in third, so in practice one tends to hang on to second in busy traffic for fear of being caught with no torque. The Greenline is yet another embodiment of an old and reliable adage: set a car up for the best possible ‘official’ test-cycle consumption figures, and you not only spoil driveability but also compromise real-world fuel economy.

But don’t get the idea that the Fabia Greenline is an unmitigated failure. Far from it: rather, it is a car of two halves.

Faced with an open road, the excellent torque and long gearing start to work for you rather than against you.

Across country, third gear is splendid for pulling firmly and decisively out of bends or for 30-50mph overtaking. Fourth runs at a loping 25mph/1000rpm and offers relaxed off-motorway cruising — just don’t expect any overtaking urge below about 50mph.

The Greenline’s motorway performance is little short of revelatory, and confidently confirms a belief we have long held: that the current cohort of small turbodiesels are pointlessly undergeared in top.

The highest of the little Škoda’s five gears runs at 32mph/1000rpm. Those used to driving cars with atmospheric engines might well look askance at this figure, but the Fabia’s turbodiesel makes light work of it. On the motorway, the Greenline is as relaxing a small car as you could wish for. Maintaining a true 70mph (76mph on the speedometer) is effortless, even on long motorway gradients. At this speed, the engine is turning over at a relaxed 2200rpm: bang on top of the torque curve.

We were not able to verify Škoda’s figures for outright performance, but driven flat-out from rest the Greenline is certainly more than adequately quick for any of its likely buyers. Changing up at the engine’s 4000rpm power peak allows rapid progress. Gearbox synchromesh under duress proved solid if a sometimes a tad slow, though oddly there were occasional signs of weak synchro in first and second gears during more relaxed driving.

Although the TDI will easily run beyond its 4000rpm power peak, there is no point in venturing into this territory. The engine management system cranks the injection timing forward and power falls off sharply.

In the table below we have compared the internal gear ratios of the Greenline with those of the ‘normal’ TDI 80, and also indicated the engine speeds at which you need to change up to leave the car at 2000rpm in the next gear. This gives a measure of how easy it is for the driver to make good progress.

Škoda Fabia
Greenline
Fabia
TDI 80
I 3.78 3.30
I-II 3670rpm 3400rpm
II 2.06 1.94
II-III 3300rpm 2960rpm
III 1.25 1.31
III-IV 3000rpm 2700rpm
IV 0.84 0.97
IV-V 2550rpm 2550rpm
V 0.66 0.76
R 3.60 3.06
Final drive 3.158 3.389

Over our mixed test route, the Greenline returned 53.3mpg, after correcting for the trip-meter’s very modest 0.5 per cent. optimism. The mileage consisted of a broad spectrum of town driving, motorway work and cross-country motoring. A preponderance of open-road cruising will certainly improve on this figure, but it doesn’t take much urban driving to knock it back again.

It’s worth noting a couple of points. First, that our test mileage always includes spells of quite gentle motoring, to the extent that we don’t feel that our figures represent the rock bottom of what an owner could expect — especially if the owner happens to live and drive in town. Secondly, in the case of the Greenline, the trip computer’s journey average MPG figures were invariably wildly optimistic.

:Next page

Photo copyright © Škoda U.K.
All content copyright © Under the Skin 2010 unless otherwise stated. We recommend Firefox.