 | This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these messages)
|
| Honda R engine | |
|---|---|
 | |
| Overview | |
| Manufacturer | Honda Motor Co Ltd |
| Production | 2006–present |
| Layout | |
| Configuration | Naturally aspirated Straight-4 |
| Displacement | 1.6–2.0 L; 97.3–121.9 cu in (1,595–1,997 cc) |
| Cylinder bore | 81 mm (3.19 in) |
| Piston stroke | 77.4 mm (3.05 in) 87.3 mm (3.44 in) 96.9 mm (3.81 in) |
| Cylinder block material | Aluminum alloy |
| Cylinder head material | Aluminum alloy |
| Valvetrain | SOHC 4 valves x cyl. with i-VTEC DOHC 4 valves x cyl. with i-VTEC (LF Hybrid engine) |
| Compression ratio | 10.5:1-10.7:1 |
| RPM range | |
| Max. engine speed | 6800 |
| Combustion | |
| Fuel system | PGM-FI |
| Fuel type | Gasoline |
| Cooling system | Water-cooled |
| Output | |
| Power output | 125–156 PS (92–115 kW; 123–154 bhp) |
| Torque output | 15.4–19.4 kg⋅m (151–190 N⋅m; 111–140 lb⋅ft) |
The Honda R engine is an inline-four engine launched in 2006 for the Honda Civic (non-Si). It is fuel injected, has an aluminum-alloy cylinder block and cylinder head, is a SOHC 16-valve design (four valves per cylinder) and utilizes Honda's i-VTEC system. The R series engine has a compression ratio of 10.5:1, features a "drive by wire" throttle system which is computer controlled to reduce pumping losses and create a smooth torque curve.
The engine uses many advanced technologies to improve fuel economy and reduce friction. Piston rings are given an ion plating and weight is reduced with plastic and aluminum parts and variable length intake manifolds that maintain ram air at a wide RPM range. The engine also features piston cooling jets, previously available only on high performance engines, and in the ninth-generation 1.8L Civic (2012-2015) the pistons are treated with molybdenum disulfide applied in a polka-dot pattern. The automatic transmission model is rated at California Air Resources Board (CARB) ULEV-2 (Ultra Low Emissions Vehicle) with fuel economy 25 mpg‑US (9.4 L/100 km; 30 mpg‑imp) city, and 36 mpg‑US (6.5 L/100 km; 43 mpg‑imp) highway. It also uses the same computer (engine control unit) controlled distributorless coil-on-plug ignition as the Honda K-series engines. As of September 2019, the R series engines were only offered outside of Japan.