The Fiat X 1/9 (128 AS) 1.5 Five Speed, producing 76 horsepower, represents a significant iteration of the iconic Italian sports car. Produced between 1985 and 1989, this variant occupied a middle ground within the X 1/9 lineup, offering a balance between affordability and driving engagement. It built upon the foundation laid by the earlier 1.3-liter models, providing a modest power increase and a five-speed manual transmission that enhanced the driving experience. The X 1/9, as a whole, was notable for its mid-engine, rear-wheel-drive layout – a relatively uncommon configuration for production cars of its era – and its distinctive Bertone-designed targa top.
Technical Specifications
| Brand | Fiat |
| Model | X 1/9 |
| Generation | X 1/9 (128 AS) |
| Type (Engine) | 1.5 Five Speed (76 Hp) |
| Start of production | 1985 |
| End of production | 1989 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Targa |
| Seats | 2 |
| Doors | 2 |
| Fuel Type | Petrol (Gasoline) |
| Power | 76 Hp @ 5600 rpm |
| Power per litre | 50.7 Hp/l |
| Engine layout | Middle, Transverse |
| Engine Model/Code | 138 BS.031 |
| Engine displacement | 1499 cm3 |
| Engine displacement (US) | 91.47 cu. in. |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Cylinder Bore | 86.4 mm |
| Cylinder Bore (US) | 3.4 in. |
| Piston Stroke | 63.9 mm |
| Piston Stroke (US) | 2.52 in. |
| Compression ratio | 9.2:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Engine oil capacity | 4.5 l |
| Engine oil capacity (US) | 4.76 US qt |
| Engine oil capacity (UK) | 3.96 UK qt |
| Coolant | 11.5 l |
| Coolant (US) | 12.15 US qt |
| Coolant (UK) | 10.12 UK qt |
| Length | 3970 mm |
| Length (US) | 156.3 in. |
| Width | 1570 mm |
| Width (US) | 61.81 in. |
| Height | 1180 mm |
| Height (US) | 46.46 in. |
| Wheelbase | 2200 mm |
| Wheelbase (US) | 86.61 in. |
| Front track | 1350 mm |
| Front track (US) | 53.15 in. |
| Rear track | 1335 mm |
| Rear track (US) | 52.56 in. |
| Ride height (ground clearance) | 125 mm |
| Ride height (ground clearance) (US) | 4.92 in. |
| Drivetrain | Rear wheel drive |
| Number of gears | 5 |
| Gearbox type | Manual transmission |
| Front suspension | Independent coil spring |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
Powertrain & Engine Architecture
The heart of the X 1/9 1.5 was the 138 BS.031 engine, a 1499 cc inline-four cylinder unit. This engine featured a cast iron block and an aluminum cylinder head, contributing to a relatively lightweight construction. The 76 horsepower output was achieved through a combination of a slightly higher compression ratio (9.2:1) compared to earlier models and the adoption of multi-port fuel injection. This system, while not as sophisticated as later electronic fuel injection systems, provided a noticeable improvement in throttle response and fuel efficiency over carbureted setups. The engine utilized a single overhead camshaft (SOHC) valvetrain with two valves per cylinder. The five-speed manual transmission, a key upgrade for this variant, offered closer gear ratios, allowing the driver to keep the engine within its optimal power band more effectively. This was particularly beneficial for spirited driving and navigating winding roads.
Driving Characteristics
The 1.5-liter, 76 hp X 1/9 offered a distinctly engaging driving experience, albeit one that wasn’t about outright speed. Acceleration was adequate, with a 0-60 mph time estimated around 11-12 seconds. However, the car’s true appeal lay in its handling. The mid-engine layout provided excellent balance and predictable cornering behavior. The five-speed transmission allowed for precise gear selection, maximizing the available power. Compared to the earlier 1.3-liter versions, the 1.5 felt more relaxed at highway speeds, with less need for frequent downshifting. While not as potent as the later 1.6-liter versions, the 1.5 offered a sweet spot for drivers who prioritized handling and driver involvement over sheer horsepower. The relatively light weight of the vehicle (around 2200 lbs) further enhanced its agility.
Equipment & Trim Levels
The X 1/9 1.5 Five Speed typically came equipped with a fairly basic, but functional, interior. Standard features included cloth upholstery, a leather-wrapped steering wheel, and a comprehensive instrument panel displaying speed, tachometer, fuel level, coolant temperature, and oil pressure. Power steering was not standard, contributing to the car’s direct steering feel. Optional extras included air conditioning, a sunroof (in addition to the targa top), and upgraded audio systems. The interior design was minimalist, reflecting the car’s sporting intentions. The targa top, a defining feature of the X 1/9, provided an open-air driving experience while maintaining a degree of structural rigidity.
Chassis & Braking
The X 1/9 featured an independent coil spring suspension at all four wheels, providing a comfortable ride and good handling characteristics. The front suspension utilized MacPherson struts, while the rear employed a semi-trailing arm design. Braking duties were handled by ventilated discs at the front and solid discs at the rear. While adequate for the car’s performance, the braking system wasn’t particularly powerful by modern standards. The car’s relatively light weight helped to mitigate this limitation. A stabilizer bar was fitted at the front to reduce body roll during cornering.
Market Reception & Comparison
The X 1/9 1.5 Five Speed was generally well-received by automotive critics. It was praised for its handling, styling, and unique mid-engine layout. However, some reviewers noted the engine’s modest power output and the car’s somewhat cramped interior. Compared to the 1.3-liter versions, the 1.5 offered a noticeable improvement in performance and refinement. Compared to the later 1.6-liter models, it lacked the same level of outright speed, but it was often considered more affordable and easier to maintain. Fuel economy was reasonable for a sports car of its era, averaging around 25-30 mpg.
Legacy
The Fiat X 1/9, and specifically the 1.5 Five Speed variant, has developed a devoted following among classic car enthusiasts. The 138 BS.031 engine, while not known for being exceptionally robust, is generally reliable if properly maintained. Common issues include oil leaks and wear in the timing chain. Parts availability can be challenging, but a network of specialist suppliers exists to support owners. Today, the X 1/9 is appreciated for its unique design, engaging driving experience, and relative affordability. It represents a distinctive chapter in Fiat’s history and a testament to the creativity of Bertone’s design studio. Well-maintained examples are increasingly sought after by collectors and enthusiasts who appreciate its classic Italian charm.
