| 摘要 |
PURPOSE:To improve fuel consumption without deteriorating operability by properly judging whether lean burning control is able to be carried out or not. CONSTITUTION:A reference value KBSM of a target air-fuel ratio is computed by using a KBSM map which includes a leaner value than a theoretical air-fuel ratio and a KTWLAF table which does not include a lean value (steps S29, S24). When a shifting position of a transmission is a fifth-speed position, the KBSM map is utilized in case that an engine water temperature TW is equivalent to a first specified water temperature TWLEAN5 or higher, and it is judged that lean burning control is enabled (steps S21 to S23, 29). On the other hand, the shifting position is other than the fifth-speed position, the lean burning control is enabled in case that the engine water temperature TW is equivalent to a second specified water temperature TWLEAN or higher, which TWLEAN is higher than the first water temperature TWLEAN5. |
