For controlling injection of a mixture fuel of ethanol and gasoline in an internal combustion engine, ethanol concentration of the mixture fuel supplied to the engine is detected, target operation information related to the engine is obtained, a division scheme of a plurality of injection regions is determined based on the ethanol concentration, an injection region corresponding to the target operation information is determined in the determined division scheme of injection regions corresponding to the ethanol concentration, and while performing injection of the mixture fuel corresponding to the determined injection region, at least one of injection timing and injection duration of the mixture fuel is varied according to the ethanol concentration.

A control device for an engine includes an electronic control unit configured to estimate a water content mixed in engine oil based on a history of a fuel injection amount during an operation of the engine and restrain freezing of water such that, when the water content thus estimated is a predetermined amount or more, the electronic control unit increases a mixing amount of the fuel into the engine oil as compared with a case where the water content thus estimated is less than the predetermined amount. The control device estimates the water content mixed in the engine oil as a function of an integrated value of water content while an oil temperature of the engine is less than a predetermined temperature.

A vehicle includes an engine and a controller programmed to, responsive to an estimated oil dilution level of the engine exceeding a first threshold, issue commands such that regenerative braking is inhibited to increase a temperature of the engine, and responsive to the estimated oil dilution level falling below the first threshold, discontinue issuing the commands.

Methods and systems are provided for synergizing the benefits of a multi-fuel engine in a hybrid vehicle system. During engine operation, in response to a change in driver demand, the controller may opt to switch fuels or maintain a current fuel while using stored power assist. The selection may be based on the combination of fuel and stored power offset that provides the highest engine efficiency at the lowest fuel cost.

The present invention describes a fuel-management system for minimizing particulate emissions in turbocharged direct injection gasoline engines. The system optimizes the use of port fuel injection (PFI) in combination with direct injection (DI), particularly in cold start and other transient conditions. In the present invention, the use of these control systems together with other control systems for increasing the effectiveness of port fuel injector use and for reducing particulate emissions from turbocharged direct injection engines is described. Particular attention is given to reducing particulate emissions that occur during cold start and transient conditions since a substantial fraction of the particulate emissions during a drive cycle occur at these times. Further optimization of the fuel management system for these conditions is important for reducing drive cycle emissions.

In a flexible-fuel engine capable of using fuel containing alcohol as fuel to be combusted in a cylinder, the geometric compression ratio is set to 12 or more, the engine is started by using fuel containing alcohol, an intake valve closing timing at an engine start time is set to an advance angle side than a first reference timing being a timing corresponding to a most retarded angle position out of intake valve closing timings capable of starting the engine in combusting fuel of alcohol 100% in the cylinder at a first intake temperature, and is set to a timing on a retarded angle side than a second reference timing being a timing corresponding to a most advanced angle position out of intake valve closing timings capable of avoiding pre-ignition in combusting fuel of gasoline 100% at an engine start time at a second intake temperature.

An ignition timing control device for an internal combustion engine including: a setting unit configured to set a target ignition timing of the internal combustion engine based on a reference ignition timing and an advance correction amount; a start determination unit configured to determine, based on change in an alcohol concentration, whether or not the fuel injected from a fuel injection valve starts to switch from a first fuel to a second fuel higher in the alcohol concentration than the first fuel; a completion determination unit configured to determine whether or not switching to the second fuel is completed; a restriction unit configured to restrict the advance correction amount during a switching period to the advance correction amount corresponding to the alcohol concentration of the first fuel or lower; and a cancel unit configured to cancel restriction of the advance correction amount after the completion of the switching is determined.

Fuel management system for enhanced operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder. It is preferred that the direct injection occur after the inlet valve is closed. It is also preferred that stoichiometric operation with a three way catalyst be used to minimize emissions. In addition, it is also preferred that the anti-knock agents have a heat of vaporization per unit of combustion energy that is at least three times that of gasoline.

An object of this invention is, in an internal combustion engine having of in-cylinder direct injection and port injection, to enable the early elimination of a difference between fuel concentrations of fuel injected from different injection valves that can arise when a mixing ratio of different kinds of fuel contained in the fuel that is used changes significantly. To achieve this, the control device of this invention normally controls a fuel injection amount of each injection valve in accordance with the operating state of the internal combustion engine, while a change arose in the mixing ratio of different kinds of fuel contained in the fuel that is used or while there is a possibility for such a change, the control device controls a fuel injection amount of each injection valve so that fuel is temporarily injected from both the in-cylinder injection valve and the port injection valve.

A control apparatus is applied to an internal combustion engine in which fuel used for operation is changed between liquid fuel containing alcohol and gas fuel. The control apparatus includes an electronic control unit configured to prohibit use of the gas fuel when a ratio of dilution of lubricating oil by the liquid fuel in a lubricating oil storage portion of the internal combustion engine is equal to or larger than a predetermined value or when an amount of the liquid fuel mixed in the lubricating oil in the lubricating oil storage portion is equal to or larger than a predetermined amount.