The Vauxhall Astra Mk V Convertible 1.9 CDTi, produced between 2006 and 2011, represented a compelling offering in the compact convertible segment. Positioned as a mid-range trim within the Mk V Astra Convertible lineup, it combined the practicality of a four-seater convertible with the fuel efficiency and torque characteristics of a modern common-rail diesel engine. This variant aimed to appeal to buyers seeking a stylish open-top experience without sacrificing everyday usability or incurring the higher costs associated with petrol-powered alternatives or higher-performance trims. It was primarily marketed in Europe, particularly the United Kingdom, where Vauxhall held a significant market share.
Technical Specifications
| Brand | Vauxhall |
| Model | Astra |
| Generation | Astra Mk V Convertible |
| Type (Engine) | 1.9 CDTi (150 Hp) |
| Start of production | 2006 |
| End of production | 2011 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe – Cabriolet |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (economy) – urban | 7.6 l/100 km (30.9 US mpg, 37.2 UK mpg, 13.2 km/l) |
| Fuel consumption (economy) – extra urban | 5.1 l/100 km (46.1 US mpg, 55.4 UK mpg, 19.6 km/l) |
| Fuel consumption (economy) – combined | 6 l/100 km (39.2 US mpg, 47.1 UK mpg, 16.7 km/l) |
| CO2 emissions | 165 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 9.5 sec |
| Acceleration 0 – 62 mph | 9.5 sec |
| Acceleration 0 – 60 mph | 9 sec |
| Maximum speed | 212 km/h (131.73 mph) |
| Emission standard | Euro 4 |
| Weight-to-power ratio | 11 kg/Hp, 90.6 Hp/tonne |
| Weight-to-torque ratio | 5.3 kg/Nm, 190.2 Nm/tonne |
| Power | 150 Hp @ 4000 rpm |
| Power per litre | 78.5 Hp/l |
| Torque | 315 Nm @ 2000 rpm (232.33 lb.-ft. @ 2000 rpm) |
| Engine layout | Front, Transverse |
| Engine Model/Code | Z19DTH |
| Engine displacement | 1910 cm3 (116.56 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Cylinder Bore | 82 mm (3.23 in.) |
| Piston Stroke | 90.4 mm (3.56 in.) |
| Compression ratio | 17.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Turbocharger, Intercooler |
| Engine oil capacity | 4.3 l (4.54 US qt | 3.78 UK qt) |
| Coolant | 7 l (7.4 US qt | 6.16 UK qt) |
| Kerb Weight | 1656 kg (3650.86 lbs.) |
| Max. weight | 1865 kg (4111.62 lbs.) |
| Max load | 209 kg (460.77 lbs.) |
| Trunk (boot) space – minimum | 205 l (7.24 cu. ft.) |
| Trunk (boot) space – maximum | 440 l (15.54 cu. ft.) |
| Fuel tank capacity | 52 l (13.74 US gal | 11.44 UK gal) |
| Length | 4476 mm (176.22 in.) |
| Width | 1759 mm (69.25 in.) |
| Width including mirrors | 2021 mm (79.57 in.) |
| Height | 1411 mm (55.55 in.) |
| Wheelbase | 2614 mm (102.91 in.) |
| Front track | 1491 mm (58.7 in.) |
| Rear (Back) track | 1481 mm (58.31 in.) |
| Ride height (ground clearance) | 130 mm (5.12 in.) |
| Drag coefficient (Cd) | 0.31 |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the front wheels of the vehicle. |
| Drive wheel | Front wheel drive |
| Number of gears and type of gearbox | 6 gears, manual transmission |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Tires size | 225/45 R17 |
| Wheel rims size | 17 |
Powertrain & Engine Architecture
The heart of the Astra Mk V Convertible 1.9 CDTi is the Z19DTH engine, a 1.9-liter inline-four cylinder diesel. This engine is a member of the GM/Fiat family of common-rail direct injection diesels. It features a 16-valve cylinder head and a variable geometry turbocharger with an intercooler, contributing to its respectable power output and torque delivery. The common-rail direct injection system, operating at very high pressures, ensures efficient fuel atomization and precise control over combustion. The engine’s 17.5:1 compression ratio is typical for a diesel engine, maximizing thermal efficiency. The 150 horsepower and 315 Nm (232 lb-ft) of torque were delivered at 4000 rpm and 2000 rpm respectively. The engine was paired with a six-speed manual transmission, providing a good balance between fuel economy and driver control. While an automatic transmission was offered on other Astra Mk V models, it wasn’t typically paired with the 1.9 CDTi engine in the convertible variant.
Driving Characteristics
The 1.9 CDTi engine in the Astra Mk V Convertible provided a noticeably different driving experience compared to the petrol-powered versions. While lacking the outright acceleration of the higher-horsepower petrol engines, the diesel offered significantly more torque, particularly at lower engine speeds. This translated to strong pulling power for overtaking and effortless cruising. The six-speed manual transmission allowed drivers to keep the engine in its optimal torque band, maximizing efficiency and responsiveness. The convertible’s weight (approximately 1656 kg) did impact performance somewhat, resulting in a 0-60 mph time of around 9 seconds. However, the focus was more on relaxed, comfortable touring than outright sporty performance. The gear ratios were well-chosen to balance acceleration and fuel economy, making it a practical choice for long journeys.
Equipment & Trim Levels
The 1.9 CDTi Convertible typically came with a reasonable level of standard equipment. This included air conditioning, electric front windows, a CD stereo, alloy wheels, and ABS brakes. Higher trim levels, such as the Design or SE, added features like climate control, upgraded upholstery, parking sensors, and rain-sensing wipers. The interior generally featured a functional, if somewhat understated, design. Upholstery options included cloth or leather, and dashboard trim was typically dark grey or black. Optional extras included a panoramic sunroof, heated seats, and a premium sound system.
Chassis & Braking
The Astra Mk V Convertible utilized a MacPherson strut front suspension and a torsion beam rear suspension. This setup provided a reasonable compromise between ride comfort and handling. The front brakes were ventilated discs, while the rear brakes were solid discs. ABS (Anti-lock Braking System) was standard. The steering was a rack and pinion system, offering decent feedback and precision. Stabilizer bars were fitted to both the front and rear axles to reduce body roll during cornering. The suspension was tuned to prioritize comfort, but it still provided adequate control for everyday driving.
Market Reception & Comparison
The Astra Mk V Convertible 1.9 CDTi was generally well-received by automotive critics. It was praised for its fuel efficiency, strong torque, and comfortable ride. However, some reviewers noted that the diesel engine was somewhat noisy compared to petrol alternatives. Compared to the 1.8-liter petrol version, the 1.9 CDTi offered significantly better fuel economy and more torque, but slightly slower acceleration. The diesel also tended to hold its value slightly better in the used car market. Compared to other convertibles in its class, such as the Peugeot 206 CC and Renault Megane Coupe Cabriolet, the Astra offered a good balance of practicality, style, and affordability.
Legacy
The Z19DTH engine, while generally reliable, is known to have some potential issues, including problems with the turbocharger and the diesel particulate filter (DPF). Regular maintenance, including oil changes and DPF regeneration, is crucial for ensuring long-term reliability. Today, the Astra Mk V Convertible 1.9 CDTi represents an affordable entry point into the world of open-top motoring. Well-maintained examples are still relatively common on the used car market, and they offer a practical and enjoyable driving experience. Its fuel efficiency and torque make it a suitable choice for those seeking a comfortable and economical convertible.
