A fuel maintenance guide system in hybrid vehicles in which a shift to the fuel maintenance mode giving priority to consuming fuel is executed automatically under a predetermined condition regardless of intention of a driver, the fuel maintenance guide system including: a residual fuel detecting unit detecting a residual amount of the fuel; a cancel condition determining unit determining a cancel condition for cancelling the shift to the fuel maintenance mode, based on the residual amount detected by the residual fuel detecting unit; and a displaying unit displaying the cancel condition determined by the cancel condition determining unit from a predetermined time period before the shift to the fuel maintenance mode.

A fuel maintenance guide system in hybrid vehicles in which a shift to the fuel maintenance mode giving priority to consuming fuel is executed automatically under a predetermined condition regardless of intention of a driver, the fuel maintenance guide system including: a residual fuel detecting unit detecting a residual amount of the fuel; a cancel condition determining unit determining a cancel condition for cancelling the shift to the fuel maintenance mode, based on the residual amount detected by the residual fuel detecting unit; and a displaying unit displaying the cancel condition determined by the cancel condition determining unit from a predetermined time period before the shift to the fuel maintenance mode.

A fuel maintenance guide system is provided in a hybrid vehicle in which a shift to a fuel maintenance mode prioritizing consumption of fuel is automatically performed under a predetermined condition regardless of a driver's intention. The fuel maintenance guide system includes an information notification unit configured to perform notification of information urging consumption of the fuel, and a control unit configured to estimate a time to shift automatically to the fuel maintenance mode and to begin to perform notifying actuation of the information notification unit a predetermined period of time before the estimated time.

A hybrid electric vehicle system comprises an internal combustion (IC) engine and an electric engine providing power to a drive shaft of the vehicle. The IC engine receives a fuel from a fuel tank. Exhaust gases from the IC engine are treated at an exhaust treatment apparatus including a reagent tank containing a reagent. A controller monitors a quality of the fuel in the fuel tank and the reagent in the reagent tank and if needed, initiates fuel degradation reduction event or a reagent degradation reduction event. These events can include running the IC engine even if a battery supplying power to the motor is not discharged. The fuel degradation reduction event includes dosing the fuel tank with an antioxidant to reduce the rate of degradation of the fuel.

A hybrid electric vehicle system comprises an internal combustion (IC) engine and an electric engine providing power to a drive shaft of the vehicle. The IC engine receives a fuel from a fuel tank. Exhaust gases from the IC engine are treated at an exhaust treatment apparatus including a reagent tank containing a reagent. A controller monitors a quality of the fuel in the fuel tank and the reagent in the reagent tank and if needed, initiates fuel degradation reduction event or a reagent degradation reduction event. These events can include running the IC engine even if a battery supplying power to the motor is not discharged. The fuel degradation reduction event includes dosing the fuel tank with an antioxidant to reduce the rate of degradation of the fuel.

A control apparatus of a plug-in hybrid electric vehicle that is provided with a fuel tank, an engine, a battery, and an electric motor. The battery is chargeable by an external power source. The control apparatus includes a fuel deterioration determiner and a regeneration amount limiter. The fuel deterioration determiner determines whether a fuel stored in the fuel tank is deteriorated. The regeneration amount limiter reduces, when the fuel is determined by the fuel deterioration determiner as being deteriorated, a regeneration amount to be less than the regeneration amount of a case where the fuel is determined by the fuel deterioration determiner as not being deteriorated. The regeneration amount is an amount of regeneration of electric power generated by the electric motor upon deceleration of the plug-in hybrid electric vehicle.

A control apparatus of a plug-in hybrid electric vehicle that is provided with a fuel tank, an engine, a battery, and an electric motor. The battery is chargeable by an external power source. The control apparatus includes a fuel deterioration determiner and a regeneration amount limiter. The fuel deterioration determiner determines whether a fuel stored in the fuel tank is deteriorated. The regeneration amount limiter reduces, when the fuel is determined by the fuel deterioration determiner as being deteriorated, a regeneration amount to be less than the regeneration amount of a case where the fuel is determined by the fuel deterioration determiner as not being deteriorated. The regeneration amount is an amount of regeneration of electric power generated by the electric motor upon deceleration of the plug-in hybrid electric vehicle.

A method for controlling a pressure inside a fuel tank system including a fuel tank and a controllable pressure relief valve. The method includes assessing whether a predetermined vapor expulsion risk is present, the predetermined vapor expulsion risk pertaining to a vapor expulsion from a main volume of the tank into a space accessible to an operator; if said risk is present, operating the pressure relief valve in accordance with a first pressure threshold, if the risk is not present, operating the pressure relief valve in accordance with a second pressure threshold which is higher than the first pressure threshold.

A method for controlling a pressure inside a fuel tank system including a fuel tank and a controllable pressure relief valve. The method includes assessing whether a predetermined vapor expulsion risk is present, the predetermined vapor expulsion risk pertaining to a vapor expulsion from a main volume of the tank into a space accessible to an operator; if said risk is present, operating the pressure relief valve in accordance with a first pressure threshold, if the risk is not present, operating the pressure relief valve in accordance with a second pressure threshold which is higher than the first pressure threshold.

A method comprises on board a hybrid vehicle and executed by a vehicle controller on board the hybrid vehicle, determining a pH based on a pH sensor positioned in a fuel system; and in response to a first condition comprising the pH being less than a first threshold pH, disabling an electric motor and propelling the hybrid vehicle with an engine. In this way, a risk of engine degradation due to fuel degradation can be reduced.