Saab 9-5 2.0 TTiD Aero

What is it?

The range-topping 'TTiD' diesel version of Saab's 9-5 saloon, complete with a brand new twin-turbocharged 2.0-litre diesel engine that will also end up powering the Vauxhall Insignia.

And it's a car with plenty of weight on its shoulders. The various ranks of the UK motoring press have, as one, voiced the same criticisms of Saab's lesser 2.0-litre TiD '160' 9-5: there's no shortage of consensus that it's a car short on performance and refinement, and doesn't ride or handle well enough on UK roads.

To its credit, Saab has responded to these criticisms. This month it has beefed up standard 'Vector SE' specification on the 9-5 to include full leather seats and 18in wheels. More importantly, it has reappraised the chassis settings of the standard, passively damped 2.0-litre TiD 9-5 towards a more comfortable set-up with lower spring- and damper rates, softer anti-roll bars and more wheel travel.

And at the same time, Saab has launched this 187bhp, twin-turbocharged 'TTiD' 9-5. Not only does it get better performance than the 158bhp TiD, but it's offered with optional 'XWD' four-wheel drive. Which means that even the front-drivers get Saab's more sophisticated 'Linked H-arm' rear suspension.

What's it like?

This new engine is much more responsive than Saab's regular, single-turbo 2.0-litre diesel. Performance below 2500rpm is much less lethargic than it was in our road test car, and engine refinement below 3000rpm is better too. The 9-5 hardly feels fast, even in this guise, due to those tall gear ratios – but at least this one's quieter and easier to drive at normal crank speeds.

Our test car came in 'Aero' specification, on Sport suspension and 19in alloys: a verdict on the 9-5's new comfier standard chassis set-up will therefore have to wait.

However, with Saab's 'DriveSense' continuously active dampers and variable steering assistance systems onboard (neither of which our original road test car had fitted), this test car certainly rode and steered better than we expected. In 'Comfort' mode, its chassis soaked up urban bumps and troughs quite well. It also had better high-speed body control, and subjected occupants to less head toss, than our road test car.

Should I buy one?

This new version of the 9-5 proves that, if you dress it with the right options and go for the latest diesel engine, you can make this Saab meet most class standards. Spongy, lifeless steering and a determinedly unexciting chassis mean it'll never be a driver's car, but it's certainly spacious and attractive and – with this engine, at least - quite well-mannered.

Pricing levels almost at eye level with BMW's 525d and Mercedes' E250 CDi make this 9-5 a tough car to recommend, but it certainly shows that, after an inauspicious early showing, Saab's biggest saloon is now developing in the right direction.

Saab 9-5 2.0 TTiD Aero

Price: £32,165; Top speed: 143mph; 0-62mph: 8.5sec; Economy: 47.1mpg; Co2: 159g/km; Kerb weight: 1750kg (tbc); Engine type: 4cyls in line, 1956cc, twin turbodiesel; Power: 187bhp at 4000rpm; Torque: 295lb ft at 1750rpm; Gearbox: 6spd manual