Motohashi, Y., Kubota, K., Akaishi, N., Ishiki, K. et al., "Development of New L4 2.4L Gasoline Engine for 2013 Model Year ACCORD," SAE Technical Paper 2013-01-1734, 2013, doi:10.4271/2013-01-1734.
A new 2.4 L, i-VTEC 4-cylinder direct injection gasoline engine which achieved both low CO₂ emissions performance and high power was developed as a next-generation Honda engine series. This new engine applied a direct injection system with high-pressure multi-hole injectors. The inlet head port and combustion chamber shapes, injector spray pattern, and fuel injection control have been optimized to achieve homogeneous mixture for stable and highly efficient combustion. Friction was also reduced by adopting new engine structure.As a result, both the power and torque was increased by up to 10%, fuel consumption was improved by 5%. A 2013 year model ACCORD, which is equipped with this new engine, a highly efficient CVT transmission, and chassis improvement, achieved 11% improvement in label combined fuel economy and the Partial credit Zero Emission Vehicle (PZEV) level of low emissions in CARB emissions regulations. In addition, the new structure engine achieved weight reduction with even better NVH performance than a previous model by optimizing cylinder block stiffness.