The Fiat X 1/9, specifically the 128 AS variant with the 1.5-liter engine and five-speed manual transmission producing 85 horsepower, represents a unique chapter in Italian automotive history. Produced from 1978 to 1989, this iteration of the X 1/9 was positioned as the enthusiast’s choice within the model range, offering a more engaging driving experience than the earlier, lower-powered versions. It was a direct response to criticisms of the original X 1/9’s performance, aiming to deliver a more spirited and refined driving experience while retaining the distinctive targa top styling. The X 1/9, as a whole, was a significant departure for Fiat, being a mid-engined, rear-wheel-drive sports car – a configuration rarely seen in vehicles of its price point.
Technical Specifications
| Brand | Fiat |
| Model | X 1/9 |
| Generation | X 1/9 (128 AS) |
| Type (Engine) | 1.5 Five Speed (85 Hp) |
| Start of production | 1978 |
| End of production | 1989 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Targa |
| Seats | 2 |
| Doors | 2 |
| Fuel consumption (combined) | 6.8 l/100 km |
| Fuel consumption (US mpg) | 34.6 US mpg |
| Fuel consumption (UK mpg) | 41.5 UK mpg |
| Fuel consumption (km/l) | 14.7 km/l |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 11.7 sec |
| Acceleration 0 – 62 mph | 11.7 sec |
| Acceleration 0 – 60 mph | 11.1 sec |
| Maximum speed | 180 km/h (111.85 mph) |
| Power | 85 Hp @ 5500 rpm |
| Power per litre | 57.4 Hp/l |
| Engine layout | Middle, Transverse |
| Engine Model/Code | 138 AS.000 |
| Engine displacement | 1481 cm3 (90.38 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Number of valves per cylinder | 2 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Engine oil capacity | 4.5 l (4.76 US qt | 3.96 UK qt) |
| Coolant capacity | 11.5 l (12.15 US qt | 10.12 UK qt) |
| Length | 3970 mm (156.3 in.) |
| Width | 1570 mm (61.81 in.) |
| Height | 1180 mm (46.46 in.) |
| Wheelbase | 2200 mm (86.61 in.) |
| Front track | 1350 mm (53.15 in.) |
| Rear track | 1335 mm (52.56 in.) |
| Ride height (ground clearance) | 125 mm (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 1/9 128 AS is the 1481cc (90.38 cu. in.) inline four-cylinder engine, designated as the 138 AS.000. This engine represented a significant upgrade over the earlier 1.3-liter units. It featured a cast iron block and an aluminum cylinder head, employing a belt-driven single overhead camshaft operating two valves per cylinder. The 128 AS benefitted from Bosch multi-port fuel injection, a substantial improvement over the carburetors used in earlier models, contributing to improved throttle response and fuel efficiency. The engine produced 85 horsepower at 5500 rpm and 89 lb-ft of torque. The five-speed manual transmission, a crucial element of the 128 AS’s appeal, provided closer gear ratios than the four-speed units found in some earlier X 1/9s, enhancing acceleration and allowing the engine to operate more effectively across a wider speed range.
Driving Characteristics
The X 1/9 1.5 Five Speed offered a noticeably more engaging driving experience than its predecessors. While not a powerhouse, the 85 hp engine, coupled with the five-speed gearbox, provided adequate performance for spirited driving on winding roads. The mid-engine layout contributed to excellent balance and handling, making the car feel nimble and responsive. Acceleration from 0 to 60 mph took around 11.1 seconds, and the car could reach a top speed of approximately 112 mph. The gear ratios were well-matched to the engine’s powerband, allowing for brisk acceleration in each gear. Compared to the earlier, lower-powered X 1/9s, the 128 AS felt significantly more capable and less strained during everyday driving. It wasn’t a car for drag strips, but it excelled at providing a fun and rewarding driving experience on back roads.
Equipment & Trim Levels
The X 1/9 128 AS was generally well-equipped for its price point. Standard features included comfortable bucket seats, a leather-wrapped steering wheel, and a comprehensive instrument panel. The interior was relatively minimalist but functional, with a focus on the driving experience. Optional extras included air conditioning, a sunroof, and upgraded audio systems. The exterior styling remained largely consistent with other X 1/9 models, featuring the distinctive targa top and sleek, wedge-shaped body. The 128 AS often featured subtle cosmetic enhancements, such as revised wheel trims and interior trim options, to differentiate it from earlier models.
Chassis & Braking
The X 1/9 featured an independent suspension system all around, utilizing coil springs and wishbones. This setup provided a comfortable ride while maintaining good handling characteristics. The front brakes were ventilated discs, offering excellent stopping power, while the rear brakes were solid discs. The steering was rack and pinion, providing precise and responsive control. The car’s relatively light weight – around 2,200 lbs – contributed to its agility and handling prowess. The suspension was tuned to provide a balance between comfort and performance, making the X 1/9 a capable and enjoyable car to drive on a variety of road surfaces.
Market Reception & Comparison
The X 1/9 128 AS was generally well-received by automotive critics, who praised its handling, styling, and improved performance compared to earlier models. It was often seen as a viable alternative to more expensive sports cars, offering a unique combination of Italian flair and affordability. Compared to other Fiat models, such as the 124 Spider, the X 1/9 offered a more modern and technologically advanced package. However, some critics noted the car’s relatively small interior and limited practicality. Fuel economy was respectable for the time, averaging around 34.6 mpg. Reliability was generally good, although some owners reported issues with the electrical system and cooling system.
Legacy
The Fiat X 1/9, particularly the 128 AS variant, has gained a devoted following among classic car enthusiasts. Its unique mid-engine layout, stylish design, and engaging driving experience have made it a sought-after vehicle in the used car market. While parts availability can be a challenge, the X 1/9 is generally considered to be a relatively reliable car when properly maintained. The 1.5-liter engine and five-speed transmission are known for their durability, and the car’s simple mechanical design makes it relatively easy to work on. Today, the X 1/9 stands as a testament to Fiat’s willingness to experiment with innovative designs and offer affordable sports cars to a wider audience. It remains a beloved and iconic vehicle for those who appreciate its unique character and driving dynamics.
