Abstract: An exemplary fluid heating method includes, among other things, operating an engine of a vehicle to heat an engine fluid during a drive cycle if the vehicle is in a fluid maintenance mode, and heating the fluid prior to the drive cycle if the vehicle is in the fluid maintenance mode and the vehicle is electrically coupled to a grid power source. An exemplary fluid heating assembly includes, among other things, an engine of an electrified vehicle, and a fluid heater that is activated to heat a fluid of the engine in response to the electrified vehicle being in a fluid maintenance mode when electrically coupled to a grid power source.

Abstract: 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.

Abstract: Systems and methods for operating a hybrid powertrain that includes an engine and a motor/generator are described. The systems and methods provide different ways to transition engine operating conditions between two low engine fuel consumption operating regions that are separated by a higher engine fuel consumption operating region. In one example, engine torque is increased at a higher rate in a fuel economy mode to increase an amount of time an engine operates in one of the two low fuel consumption operating regions.

Abstract: A system includes a processor configured to determine a unique vehicle identity. The processor is also configured to communicate with a remote database to access a vehicle profile based on the unique identity. The processor is further configured to obtain user-designated refueling preferences from the remote database and apply the refueling preferences to a current refueling transaction.

Abstract: 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.

Abstract: An exemplary fluid heating method includes, among other things, operating an engine of a vehicle to heat an engine fluid during a drive cycle if the vehicle is in a fluid maintenance mode, and heating the fluid prior to the drive cycle if the vehicle is in the fluid maintenance mode and the vehicle is electrically coupled to a grid power source. An exemplary fluid heating assembly includes, among other things, an engine of an electrified vehicle, and a fluid heater that is activated to heat a fluid of the engine in response to the electrified vehicle being in a fluid maintenance mode when electrically coupled to a grid power source.

Abstract: A method according to an exemplary aspect of the present disclosure includes, among other things, selectively powering a heating device to augment heating of an engine oil associated with an engine of a vehicle in a manner that influences an oil quality value of the engine oil.

Abstract: Systems and methods for operating a hybrid powertrain that includes an engine and a motor/generator are described. The systems and methods provide different ways to transition engine operating conditions between two low engine fuel consumption operating regions that are separated by a higher engine fuel consumption operating region. In one example, engine torque is increased at a higher rate in a fuel economy mode to increase an amount of time an engine operates in one of the two low fuel consumption operating regions.

Abstract: A method, comprising propelling a vehicle with an engine and a motor starting the engine if energy stored in an energy storage device is greater than an upper threshold level when a contaminant amount in the engine oil is greater than a threshold amount. In this way, it is possible to harmonize fuel degradation along with oil degradation, while still providing efficient vehicle and engine operation.

Abstract: Methods and systems are provided for operating an engine in a hybrid vehicle in response to fuel and water dilution of engine lubricating oil. An engine oil dilution counter may be adjusted based on a number of engine hot starts and duration of engine operation above a threshold temperature. In addition, the counter may be adjusted if the engine is started to deplete stale fuel in the fuel tank.

Abstract: Methods and systems are provided for extending an engine-off period of a hybrid vehicle while reducing engine cold-start emissions. During an engine pull-up to meet operator demand, the engine is held at a higher power for a longer duration to aggressively heat the exhaust catalyst. Subsequently, the engine is pulled up to a lower power and held at the lower power for shorter bursts of time to activate the exhaust catalyst.

Abstract: Methods and systems are provided for dynamically allocating engine torque and motor torque in a hybrid vehicle to meet operator torque demand. The allocation is adjusted by constraining the maximum engine torque allowable under selected conditions to provide a better trade-off between performance and fuel economy. A maximum engine torque that provides best fuel economy is learned during engine operation at different engine speed-load conditions based on a deviation in spark retard torque ratio from a threshold ratio as spark timing is moved to MBT.

Abstract: Methods and systems are provided for extending an engine-off period of a hybrid vehicle while reducing engine cold-start emissions. During an engine pull-up to meet operator demand, the engine is held at a higher power for a longer duration to aggressively heat the exhaust catalyst. Subsequently, the engine is pulled up to a lower power and held at the lower power for shorter bursts of time to activate the exhaust catalyst.

Abstract: Methods and systems for controlling a fuel tank isolation valve coupled to a fuel tank in a vehicle are disclosed. In one example approach, a method comprises, in response to a refuel request, actuating a fuel tank isolation valve to vent a fuel tank for refueling; and, in response to a pressure in the fuel tank below a threshold pressure after a predetermined time duration, discontinuing actuation of the fuel tank isolation valve to seal the fuel tank.

Abstract: Methods and systems are provided for extending an engine-off period of a hybrid vehicle while reducing engine cold-start emissions. During an engine pull-up to meet operator demand, the engine is held at a higher power for a longer duration to aggressively heat the exhaust catalyst. Subsequently, the engine is pulled up to a lower power and held at the lower power for shorter bursts of time to activate the exhaust catalyst.

Abstract: Methods and systems are provided for dynamically allocating engine torque and motor torque in a hybrid vehicle to meet operator torque demand. The allocation is adjusted by constraining the maximum engine torque allowable under selected conditions to provide a better trade-off between performance and fuel economy. A maximum engine torque that provides best fuel economy is learned during engine operation at different engine speed-load conditions based on a deviation in spark retard torque ratio from a threshold ratio as spark timing is moved to MBT.

Abstract: Methods and systems for controlling a fuel tank isolation valve coupled to a fuel tank in a vehicle are disclosed. In one example approach, a method comprises, in response to a refuel request, actuating a fuel tank isolation valve to vent a fuel tank for refueling; and, in response to a pressure in the fuel tank below a threshold pressure after a predetermined time duration, discontinuing actuation of the fuel tank isolation valve to seal the fuel tank.

Abstract: Methods and systems are provided for extending an engine-off period of a hybrid vehicle while reducing engine cold-start emissions. During an engine pull-up to meet operator demand, the engine is held at a higher power for a longer duration to aggressively heat the exhaust catalyst. Subsequently, the engine is pulled up to a lower power and held at the lower power for shorter bursts of time to activate the exhaust catalyst.

Abstract: Methods and systems are provided for operating an engine in a hybrid vehicle in response to fuel and water dilution of engine lubricating oil. An engine oil dilution counter may be adjusted based on a number of engine hot starts and duration of engine operation above a threshold temperature. In addition, the counter may be adjusted if the engine is started to deplete stale fuel in the fuel tank.

Abstract: A method, comprising propelling a vehicle with an engine and a motor starting the engine if energy stored in an energy storage device is greater than an upper threshold level when a contaminant amount in the engine oil is greater than a threshold amount.