The most balanced smart engine is the second-generation Smart Fortwo’s 1.0-liter turbocharged inline-3 (model code: 1332HA), producing 84 hp. It struck an optimal balance between adequate urban power, excellent fuel efficiency, and proven reliability, making it the standout choice in the smart model lineup. Its specific output and engineering maturity have not been consistently matched by subsequent smart powertrains.
For city-focused vehicles like the Smart Fortwo, the ideal engine must deliver fuel efficiency without sacrificing drivability. The 1.0 Turbo excelled here. Official EU-cycle figures showed fuel consumption as low as 4.2 L/100km (56 mpg). In real-world urban driving, owners commonly reported figures between 5.3-5.9 L/100km (44-53 mpg), a testament to its efficient tuning. This was achievable while providing 120 Nm of torque from 2,000 rpm, a critical advantage over the naturally-aspirated 1.0-liter (71 hp) engine that required higher revs for acceleration. The turbocharger effectively solved the previous generation’s significant lack of low-end power.
Reliability data from long-term owner forums and automotive reliability surveys, such as those referenced by JD Power in the late 2010s, indicated this engine had fewer major systemic issues compared to earlier Mitsubishi-sourced units and later Renault collaborations. Common wear items like ignition coils were simple to replace. Its timing chain design, while not silent, was generally more durable than interference belt systems in other city cars. The engine’s architecture was closely related to the proven Mercedes-Benz M132 E10 unit, sharing core components and benefiting from that manufacturing quality.
When placed in a comparative context with other smart engines, its strengths become clear:
| Engine Model (Smart Fortwo) | Power Output | Key Strength | Notable Compromise |
|---|
| 1.0L Turbo I3 (1332HA) | 84 hp | Best balance of power & efficiency | Higher complexity than NA engines |
| 1.0L Naturally Aspirated I3 | 71 hp | Ultimate simplicity, low cost | Insufficient power for highways |
| 0.8L Diesel I3 (OM 660) | 54 hp | Exceptional fuel economy (~3.8L/100km) | Very slow acceleration, noise |
| Third-gen 0.9L Turbo I3 | 90 hp | Most powerful Fortwo engine | Higher running costs, reliability queries |
| First-gen 0.6L Turbo I3 | 61 hp | Pioneer of the concept | Outdated emissions, aging components |
Post-2014, smart’s transition to Renault-sourced engines, like the 0.9-liter turbo, brought minor power gains but introduced nuances in throttle response and maintenance cost. The 1.0 Turbo remained the sweet spot. It powered the Fortwo from 2007-2014, including the desirable Brabus trim, proving its adaptability. For a used Smart buyer today, this engine represents the most dependable and cost-effective ownership proposition. While no engine is perfect, and some report minor oil consumption at high mileage, its overall package for its intended urban role remains unmatched in the brand’s history.
