Saab Convertible TiD

 The engine range for the 9-3 Convertible is to be rounded out with the 1.9 turbo diesel engine added to the lineup available in Europe.

With Saab’s sales up in Europe and GM hoping to turn things around there in general, this will be a welcome move.  Diesels sell well there and the 9-3 Convertible is a popular car everywhere.  Combining the model with a favoured power plant is a no-brainer.  In fact, until I read the press release, I’d taken it as given that a 9-3 Convertible with diesel already existed.

Can’t take any of this stuff for granted, huh?

A tip ‘o the hat to Jochen for the heads-up on this one.  The press release from GM Europe follows:


Diesel Power Added to Saab 9-3 Convertible Range

· Impressive 1.9 TiD common rail, direct, multiple injection engine

· 150 bhp and 320 Nm torque for sporty performance

· Excellent refinement and economy, 6.3 l/100km over combined cycle

· Close-ratio, six-speed manual gearbox as standard

· Six-speed auto option with Saab Sentronic manual selection

· Advanced, maintenance-free particulate filter as standard

The introduction of a powerful yet frugal turbo diesel engine substantially broadens the appeal of the Saab 9-3 Convertible range. Available on Linear and Arc specifications, the 150 bhp, 16-valve 1.9TiD unit is offered with a choice of six-speed manual or automatic transmissions.

This common rail, direct and multiple injection engine, successfully launched in the 9-3 Sport Sedan and SportCombi line-ups, is distinguished by a level of refinement that is just as impressive as its strong performance. An advanced, maintenance-free, exhaust particulate filter is fitted as standard.

In the Saab 9-3 Convertible, this engine is offered only in its most powerful configuration. That means 150 bhp maximum power generated at 4,000 rpm. But, even more importantly, it offers a wide spread of strong pulling power, with 90% of maximum torque available all the way from 1,750 to 3,250 rpm.  The maximum value of 320 Nm, between 2,000 and 2,750 rpm, is exceeded only by the 350 Nm of the top-of-the-range, 250 bhp, 2.8V6 Turbo gasoline engine.

Impressive performance

On the road performance is equally impressive, the engine’s distinctly sporty character further narrowing any perceptible difference between diesel and gasoline performance levels – except in the frequency of visits to the filling station.

In-gear acceleration, most important for everyday driving, is on a par with the 210 bhp gasoline engine (80 to 120 kph in fifth gear in 11.0 v 11.5 seconds), while the zero to 100 kph dash is accomplished in just 10.4 seconds (11.8 /automatic).

The driving experience is notable for a level of smoothness and refinement, together with a progressive torque build-up, that belies the presence of compression ignition.  Calibrating the movement of the electronic throttle to deliver a response similar to Saab’s gasoline engines had helped achieve this.  And the process is optimized by a low-inertia Garrett turbocharger, operating at 1.35 bar boost, with variable vane geometry (VNT), allowing the pitch of the turbine blades to be electronically adjusted for a quick pick-up at low engine speeds.

With combined cycle fuel consumption of 6.3 liter/100km (7.4/automatic) showing a 25 per cent gain over the 150 bhp, 1.8t gasoline engine, the new 1.9TiD offers an appealing combination of performance, refinement and economy. 

Sophisticated architecture

The engine consists of a four cylinder, cast-iron block and an alloy cylinder head, accommodating two, chain-driven, overhead camshafts with hydraulic tappets. It has a steel crankshaft and connecting rods, a dual-mass flywheel, a weight-saving pressure cast aluminum intake manifold and electronically-controlled exhaust gas re-circulation (EGR) for quick warm-up and low emissions.

Common rail technology provides consistently high injection nozzle pressures of 1,600 bar, independent of the prevailing engine speed or load.  This allows the use of small, multiple injections of fuel, between two and five, to release as much energy as possible from a given amount of fuel.

The Bosch ECM continually adjusts the number, frequency and size of the injections according to three main parameters: current engine speed, the requested throttle setting and engine coolant temperature.  Each injection pulse may be separated by as little as 150 microseconds, delivering a quantity of fuel as tiny as one cubic millimetre.

This extremely efficient combustion process pays dividends in a number of key areas.  Apart from improving fuel consumption, emissions and power, it is crucial in helping to iron out the strong vibrations traditionally associated with compression ignition.

Low levels of NVH (noise, vibration and harshness) inside the car are due to the engine’s advanced combustion technology as much as its careful chassis installation.  This includes the adoption of an electro/hydraulic power steering system, for improved fuel consumption, and additional tuning of the front suspension and wheel angles.

Six-speed transmissions

The high level of driving satisfaction is reflected in the standard fitment of a close-ratio, six gear manual gearbox that encourages driver involvement, complementing the sporty nature of the 1.9TiD engine and the Convertible’s chassis, with its unique ReAxs rear wheel steer characteristic.

The optional six-speed Aisin AW automatic transmission is a smooth and adaptive unit, responsive to changes in engine load, road gradient or altitude, and quickly finds the ‘right’ gear without any irritating ‘hunting’. The driver can also switch to manual control by using a sequential floor shift or optional steering wheel-mounted buttons. It features a lock-up in all forward ratios, except first.

Advanced Particulate Filter

The 1.9TiD powertrain includes the most advanced diesel particulate filter on the market.  Unlike other particulate traps, it is maintenance-free and self-cleaning, requiring no additives or periodic replacement.

Located in the exhaust system downstream of the close-coupled catalyst, the housing for the filter also includes a secondary oxidation catalyst to remove residual hydrocarbons (HC).  The exhaust gases pass through this first, before entering the filter’s ceramic core, made from a honeycomb of silicon carbide.  This is perforated along its length by a matrix of microscopic channels, which collect the particulates as deposits from the exhaust.

In order to clean the filter and keep the exhaust gas flow as free as possible, these deposits are periodically burnt off by short pulses of over-fuelling.  These briefly raise exhaust temperatures to the required level of 600º C.  The process is automatically initiated when back pressure in the exhaust system reaches a certain level and it is completely undetectable by the driver.

This innovative solution has been made possible through the fuelling flexibility provided by the engine’s multiple injection strategy.  The self-cleaning process takes place whenever necessary, irrespective of throttle load or engine temperature.

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  1. If there is already big problem to make enough PF’s for diesel cars. Then this engine option will not help to grow sales as unit numbers, but maybe economically as open top is more expensive.

  2. Looking at WIS shows the 1.9 TiD is belt driven, not chain like the old 2.2. Now they just need to build more of the most popular motor. I’m sure Tonawanda has some open time. fred

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