December 8, 2003

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First Drive:
2004 VW Jetta GLS 1.9 TDI PD
by Richard Russell

The Jetta, like its Golf sibling, is usually associated with long life and high mileage. The German engineering that prepares it for life on the high speed Autobahn and snaky roads of Europe, makes it suitable for much of Canada. The suspension has been softened for our different frost-heaved roads and lower sustained speeds, but the trade-off for slightly less prowess in the twisties is a higher level of ride comfort.

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The Jetta also comes as a complete package. While the initial price may seem higher than the competition, a careful study of the standard equipment list reveals that when similarly equipped, it may in fact be less expensive. The subject of this test - a 2004 Jetta GLS TDI sedan wears a price tag of $26,080. Looks a but pricey in light of $20,000 competitors doesn't it?. But add ABS, front, side and side curtain airbags, air conditioning, a power sliding sunroof, power windows, cruise control, electric defrost mirrors, remote central locking and four wheel disc brakes to the others and compare. Some of this is not available on the others - all of it is standard on the Jetta.

It also has a 12 volt outlet in the trunk, an eight-speaker stereo system complete with CD player, double-sided galvanized body panels, tie-down hooks on the massive flat luggage floor, height adjustable front seats and a steering wheel that adjust for both height and reach.

Other neat touches include power windows that operate with the key allowing you to raise or lower all simultaneously. The front windows feature one-touch up AND down operation.

How does the new PD system work? In a gasoline engine, a mixture of fuel and air is compressed and then ignited with an electrical spark. A diesel engine relies purely on compression to ignite the mixture. When air is compressed it heats up - ever notice how hot the pump and hose get when hand-pumping a bicycle tire or ball? The amount of compression required for ignition in a diesel engine is far greater than that used in a spark ignition engine. So upon ignition, a significantly greater force is applied to the crankshaft resulting in greater torque. The previous 1.9 litre turbo diesel engine - in fact, in most modern diesels - used a system where the fuel air mixture was introduced via a common rail. These systems generate a swirling motion of the air around the intake valves through especially designed intake ports. This motion causes faster mixture with the fuel when it is introduced and thus more complete combustion. This, in turn leaves less unburned fuel and emissions. Pumpe Duse is a new fuel management and delivery system that places a pump injector at each individual cylinder producing a finer spray for better and more efficient combustion. Instead of a pre-combustion chamber found in most diesels, fuel is injected directly into each individual combustion chamber under terrific pressure at precisely the right moment. The PD works like an overhead cam system, using cam lobes to determine the timing and amount of the spray into each cylinder. The new system reduces heat loss, results in a quieter, cleaner engine, faster cold weather starts and improved low-end torque. The PD system will be used elsewhere in the VW line-up for 2004, including a new 134-horsepower 2.0 litre diesel engine for the Passat and a 5.0 litre V10 for the Touareg giving 308 horsepower - and an astounding 555 lb. ft. of road-rippling torque.

Generally speaking, Volkswagen buyers keep their vehicles longer than others. They drive more and are more likely to opt for a manual transmission than any other manufacturer in the class. Which leads us to the subject of this week's test - a diesel Jetta with a manual gearbox - the ultimate combination of operating economy and passenger car efficiency in the affordable range.

The Jetta has received a number of minor upgrades and alterations for 2004 including new taillights, grill and side mouldings. On the inside there is a new instrument panel and cloth seat covering, pretty trivial changes indeed. The big story is the upgraded 1.9 litre TDI PD diesel engine - it's those last two letters that indicate the difference.

They stand for Pumpe Duse (pump-ah du-sah) - German for pump injector. A revolutionary system (see side bar) that injects a fine spray under high pressure directly into each cylinder, resulting in more power, improved emissions and a quieter engine. The current 1.9 TDI turbocharged four-cylinder diesel engine has earned a reputation for incredibly frugal operation while providing decent performance. In fact, this engine has accounted for quite a few converts to diesel - including yours truly. No longer smelly, noisy, gutless boat anchors, modern diesels like this have become a true alternative. Noise, vibration and odour have been all but eliminated and the production of torque - the turning or twisting force produced by an internal combustion engine - clearly surpasses that of similarly-sized gasoline engines. Torque is a measured quantity that determines acceleration and towing ability. Horsepower is derived through a calculation based on torque, and although useful at higher engine and vehicle speeds, relatively useless in judging vehicle performance in this part of the world. Torque is what gets you up to speed, while horsepower determines top speed only.

And getting up to speed is what the new PD diesel is all about. This frugal little wonder will get you in a heap of trouble in the blink of an eye. Posted speed limits are exceeded so easily it should come with a speed warning system. The wonder of torque is that you don't have to wind the engine to some silly speed to generate power; it's there from idle upwards. The Jetta 1.9 TDI PD will accelerate with gusto in any gear once engine speed reaches 1,200 rpm - and I mean gusto. Passing is a breeze and usually accomplished in fifth gear, the same with climbing hills. This much performance usually costs an arm and a leg at the pump. But once you locate a diesel pump, you'll be pleasantly surprised to discover how little of the smelly stuff this car requires.

Let's look at some numbers..

Power:

• 2003 1.9 TDI - 90 horsepower and 155 lb. ft. of torque.
• 2004 1.9 TDI PD - 100 horsepower and 177 lb. ft. of torque, improvements of 11% and 14% respectively.
• 2004 2.0 litre base gasoline engine -122 lb. ft. of torque
• 2004 1.8 litre turbo gas engine - 173 lb. ft. of torque.

Richard Russell is technical editor for Carguide magazine, a regular contributor to the Halifax Herald and Globe and Mail newspapers, owner of Advanced Driving Concepts driver training school, and a founding member of the Automobile Journalists Association of Canada.