The second generation of the W451 Smart Fortwo model, which is well-liked in Europe, was equipped with the 1.0-liter, three-cylinder Mitsubishi 3B21 engine, which was built in Japan between 2006 and 2014. The Daimler-Chrysler concern refers to this type of power unit as the Mercedes M132.
The engines 3B20, 3B20T, and 3B21T are also part of the 3B2 family.
The engine was mounted on:
- Smart Fortwo 2 (W451) in 2006 – 2014.
Specifications
| Production years | 2006-2014 |
| Displacement, cc | 999 |
| Fuel system | distributed injection |
| Power output, hp | 61 – 71 |
| Torque output, Nm | 89 – 92 |
| Cylinder block | aluminum R3 |
| Block head | aluminum 12v |
| Cylinder bore, mm | 72 |
| Piston stroke, mm | 81.8 |
| Compression ratio | 11.4 |
| Features | DOHC |
| Hydraulic lifters | no |
| Timing drive | chain |
| Phase regulator | MIVEC |
| Turbocharging | no |
| Recommended engine oil | 5W-30 |
| Engine oil capacity, liter | 3.3 |
| Fuel type | petrol |
| Euro standards | EURO 4/5 |
| Fuel consumption, L/100 km (for Smart Fortwo 2008) — city — highway — combined |
6.1 4.0 4.7 |
| Engine lifespan, km | ~200 000 |
| Weight, kg | 67 (without attachments) |
Disadvantages of the Mitsubishi 3B21 engine
There are two versions of the engine, and a straightforward modification won’t cause any issues;
The starter-alternator belt in the MHD hybrid rapidly wears out and warps;
When a belt breaks, the pump stops and the head overheats instantly.
Oil reaches the rubber rings on the candle wells after 100,000 kilometers;
Every 100,000 kilometers, valve clearances must be changed because there are no hydraulic lifters.