Honda S engine

The S series is a three-cylinder gasoline engine developed and manufactured by Honda, with a total displacement of 658 cc. The engine is intended for kei car applications and replaced the earlier Honda P engine when it first appeared in November 2011. Honda's stated goal at the time of introduction was to have the most fuel efficient engines in every class in which they are present by 2014 and to achieve a 30 percent reduction in CO₂ emissions across all of their vehicles by 2020 – which is why the engine family was marketed under the "Earth Dreams" Technology moniker. The second generation (S07B) appeared in 2017; it has the same overall displacement but is of a long-stroke design.

S07

Thanks to a lesser bore pitch, the engine could be made shorter. Combined with thinner walls in the block and elsewhere, such as the camshaft, the weight of the S07A was reduced by about 15 percent compared to the preceding P engine. Two versions of the S07A were available, one naturally aspirated and one turbocharged.

S07A (Earth Dreams)

PGM-FI DOHC 12 Valve
Displacement: 658.2 cc
Bore & stroke: 64.0 mm × 68.2 mm
Compression ratio: 11.2:1
Power: 43 kW (58 PS; 57 hp) at 7,300 rpm
Torque: 65 N⋅m (48 lb⋅ft) at 3,500 rpm
Applications:
- Honda N-One
- Honda N-Box

S07A Turbo (Earth Dreams)

PGM-FI DOHC 12 Valve
Turbocharger
Displacement: 658.2 cc
Bore & stroke: 64.0 mm × 68.2 mm
Compression ratio: 9.5:1
Power: 47 kW (63 hp; 64 PS) / 6,000 rpm
Torque: 10.6 kg⋅m (77 lb⋅ft; 104 N⋅m) / 2,600 rpm
Applications:
- Honda S660 (2015–2022)
- Honda N-One
- Honda N-Box

S07B

The S07B first appeared in the second generation N-Box in September 2017. It has a significantly longer stroke of 77.6 mm (3.06 in), which combines with a narrower, 60.0 mm (2.36 in) bore to provide a near identical displacement to that of the S07A. While power outputs are also near identical, the naturally aspirated engine is equipped with an i-VTEC variable valve timing and lift mechanism and continuously variable valve timing control mechanism, and the turbo engine is equipped with an electric wastegate valve.