The Smart Forfour (W454) 1.5 cdi (68 Hp) is a subcompact hatchback produced by Smart, a microcar manufacturer originally a joint venture between Daimler-Benz and Swatch. Introduced in 2004 and continuing through 2006, the W454 Forfour represented Smart’s attempt to expand its lineup beyond the two-seater Smart Fortwo. Unlike its smaller sibling, the Forfour was designed to accommodate four passengers and offered a more conventional hatchback configuration. While not officially sold in the United States, the Forfour was primarily marketed in Europe as an affordable and fuel-efficient city car, competing with vehicles like the Fiat Panda and Renault Twingo.
Smart Forfour (W454): A Detailed Overview
The W454 generation Forfour marked a significant departure for Smart, moving away from the ultra-compact city car philosophy towards a more practical and versatile vehicle. This model aimed to appeal to a broader customer base seeking a small, economical car suitable for both urban and occasional longer journeys. The 1.5 cdi variant, powered by a diesel engine, was a popular choice due to its excellent fuel economy and relatively low running costs. The Forfour’s design prioritized interior space and usability within a compact footprint, making it a practical option for navigating crowded city streets and parking in tight spaces.
Engine & Performance
The Smart Forfour 1.5 cdi is equipped with a 1.5-liter inline three-cylinder diesel engine, designated the OM 639.939. This engine produces 68 horsepower at 4000 rpm and 160 Nm (118.01 lb.-ft.) of torque at 1600 rpm. While not a performance-oriented vehicle, the engine provides adequate power for everyday driving. The Forfour 1.5 cdi achieves a combined fuel consumption of 4.6 liters per 100 kilometers (51.1 US mpg or 61.4 UK mpg), making it a very economical choice. Acceleration from 0 to 100 km/h (0-62 mph) takes 13.9 seconds, and the vehicle has a top speed of 160 km/h (99.42 mph). The engine utilizes a diesel commonrail fuel injection system and an overhead camshaft (OHC) valvetrain, contributing to its efficiency and relatively smooth operation. The engine’s power-to-weight ratio is 14.2 kg/Hp, and the torque-to-weight ratio is 6 kg/Nm.
Design & Features
The Smart Forfour (W454) is a five-door hatchback with seating for four adults. Its compact dimensions – 3752 mm (147.72 in.) in length, 1684 mm (66.3 in.) in width, and 1450 mm (57.09 in.) in height – make it easy to maneuver in urban environments. The Forfour’s interior is designed to maximize space, offering a surprisingly roomy cabin for its size. The rear seats can be folded down to increase cargo capacity from a minimum of 268 liters (9.46 cu. ft.) to a maximum of 910 liters (32.14 cu. ft.). Standard safety features included ABS (Anti-lock Braking System). The Forfour’s design, while functional, was not particularly groundbreaking, focusing instead on practicality and affordability. The vehicle’s relatively short wheelbase of 2500 mm (98.43 in.) contributes to its nimble handling. The Forfour’s fuel tank capacity is 47 liters (12.42 US gal or 10.34 UK gal).
Technical Specifications
| Brand | Smart |
| Model | Forfour |
| Generation | Forfour (W454) |
| Type (Engine) | 1.5 cdi (68 Hp) |
| Start of production | 2004 |
| End of production | 2006 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Hatchback |
| Seats | 4 |
| Doors | 5 |
| Fuel consumption (urban) | 5.8 l/100 km (40.6 US mpg, 48.7 UK mpg, 17.2 km/l) |
| Fuel consumption (extra urban) | 4 l/100 km (58.8 US mpg, 70.6 UK mpg, 25 km/l) |
| Fuel consumption (combined) | 4.6 l/100 km (51.1 US mpg, 61.4 UK mpg, 21.7 km/l) |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 13.9 sec |
| Acceleration 0 – 62 mph | 13.9 sec |
| Acceleration 0 – 60 mph | 13.2 sec |
| Maximum speed | 160 km/h (99.42 mph) |
| Emission standard | Euro 4 |
| Weight-to-power ratio | 14.2 kg/Hp |
| Weight-to-torque ratio | 6 kg/Nm |
| Power | 68 Hp @ 4000 rpm |
| Torque | 160 Nm @ 1600 rpm (118.01 lb.-ft. @ 1600 rpm) |
| Engine Model/Code | OM 639.939 |
| Engine displacement | 1493 cm3 (91.11 cu. in.) |
| Number of cylinders | 3 |
| Engine configuration | Inline |
| Number of valves per cylinder | 2 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Naturally aspirated |
| Valvetrain | OHC |
| Engine oil capacity | 5.4 l (5.71 US qt | 4.75 UK qt) |
| Coolant capacity | 6.6 l (6.97 US qt | 5.81 UK qt) |
| Kerb Weight | 965 kg (2127.46 lbs.) |
| Max. weight | 1450 kg (3196.7 lbs.) |
| Max load | 485 kg (1069.24 lbs.) |
| Trunk (boot) space – minimum | 268 l (9.46 cu. ft.) |
| Trunk (boot) space – maximum | 910 l (32.14 cu. ft.) |
| Fuel tank capacity | 47 l (12.42 US gal | 10.34 UK gal) |
| Length | 3752 mm (147.72 in.) |
| Width | 1684 mm (66.3 in.) |
| Height | 1450 mm (57.09 in.) |
| Wheelbase | 2500 mm (98.43 in.) |
| Drivetrain | Front wheel drive |
| Number of gears | 5 |
| Gearbox type | Manual transmission |
| Front brakes | Disc |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Tires size | 175/65 R14 |
The Smart Forfour (W454) 1.5 cdi, despite its limited availability in the US market, represents an interesting chapter in Smart’s history. It demonstrated the brand’s ambition to expand beyond the microcar segment and offer a more practical and versatile vehicle to a wider audience. While production was relatively short-lived, the Forfour remains a popular choice among European drivers seeking an economical and easy-to-drive city car.


