A method for estimating at least one ring-related parameter related to at least one piston ring may include estimating a bore distortion of a cylinder bore. The bore distortion may include a plurality of bore distortions corresponding to a plurality of respective piston locations within the cylinder bore. The method may also include receiving the bore distortion in a ring performance model configured to dynamically estimate a plurality of ring-related parameters associated with combustion in the cylinder bore during operation of the internal combustion engine. The ring performance model may be configured to receive a static data signal indicative of static parameters and a dynamic data signal indicative of dynamic parameters related to operation of the internal combustion engine. The ring performance model may be configured to estimate at least one ring-related parameter related to at least one piston ring during operation of the internal combustion engine.

A cooling structure of an engine includes a cylinder head and a coolant temperature sensor. The cylinder head gas a first water jacket for cooling a combustion chamber and a second water jacket for cooling an exhaust manifold. The cylinder head includes a joining portion where coolants from the first water jacket and the second water jacket join together. The joining portion has a first coolant passage. A second coolant passage is disposed downstream of the joining portion. The temperature sensing portion is disposed in the second coolant passage. A coolant outlet of the second water jacket is defined in the first coolant passage, and is located at a position on the cylinder head cover attachment surface side in the first coolant passage. The temperature sensing portion is located at a position on the cylinder block attachment surface side in the second coolant passage.

In some embodiments, a fuel temperature sensor is located proximate to a vehicle component that is expected to experience fuel gelling, such as near or within a fuel filter, in order to obtain temperature information that accurately reflects the likelihood of fuel gelling occurring within the component. The proximate fuel temperature sensor can provide more accurate temperature information for components such as fuel filters that are installed at the periphery of the vehicle, compared to other temperature sensors that measure oil temperatures or other temperatures of centrally located vehicle components. In some embodiments, the vehicle is automatically started when the temperature indicated by the fuel temperature sensor falls below a startup temperature threshold value, and is automatically stopped after a predetermined time period or after the temperature reaches a shutdown temperature threshold value.

A variety of methods and arrangements for reducing noise, vibration and harshness (NVH) in a skip fire engine control system are described. In one aspect, a firing sequence is used to operate the engine in a skip fire manner. A smoothing torque is determined that is applied to a powertrain by an energy storage/release device. The smoothing torque is arranged to at least partially cancel out variation in torque generated by the skip fire firing sequence. Various methods, powertrain controllers, arrangements and computer software related to the above operations are also described.

A method for estimating at least one ring-related parameter related to at least one piston ring may include estimating a bore distortion of a cylinder bore. The bore distortion may include a plurality of bore distortions corresponding to a plurality of respective piston locations within the cylinder bore. The method may also include receiving the bore distortion in a ring performance model configured to dynamically estimate a plurality of ring-related parameters associated with combustion in the cylinder bore during operation of the internal combustion engine. The ring performance model may be configured to receive a static data signal indicative of static parameters and a dynamic data signal indicative of dynamic parameters related to operation of the internal combustion engine. The ring performance model may be configured to estimate at least one ring-related parameter related to at least one piston ring during operation of the internal combustion engine.

In some embodiments, a fuel temperature sensor is located proximate to a vehicle component that is expected to experience fuel gelling, such as near or within a fuel filter, in order to obtain temperature information that accurately reflects the likelihood of fuel gelling occurring within the component. The proximate fuel temperature sensor can provide more accurate temperature information for components such as fuel filters that are installed at the periphery of the vehicle, compared to other temperature sensors that measure oil temperatures or other temperatures of centrally located vehicle components. In some embodiments, the vehicle is automatically started when the temperature indicated by the fuel temperature sensor falls below a startup temperature threshold value, and is automatically stopped after a predetermined time period or after the temperature reaches a shutdown temperature threshold value.

An example ferroelastic ceramic composition includes at least one compound having a relative chemical formula of A.sub.XB.sub.YC.sub.(1-X-Y)D. Element A, element B, and element C are independently selected from different members of the group consisting of yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. Element D is selected from the group consisting of phosphate, niobate, and tungstate. X and Y are each equal to or greater than zero and less than one. X and Y are collective less than one.

Methods and systems are provided for controlling operation of an engine of a vehicle to supply power to a power box that in turn supplies power to loads external to the vehicle. In one example, a method comprises, responsive to a request by an operator to operate an engine to power one or more loads external to the vehicle, monitoring an engine temperature and issuing an alert requesting the operator to take mitigating action to reduce the engine temperature when the engine temperature reaches a threshold temperature, and controlling a cooling fan as a function of whether or not the mitigating action is taken. In this way, fuel economy may be improved and power supply to power external loads may be optimized.

In some embodiments, a fuel temperature sensor is located proximate to a vehicle component that is expected to experience fuel gelling, such as near or within a fuel filter, in order to obtain temperature information that accurately reflects the likelihood of fuel gelling occurring within the component. The proximate fuel temperature sensor can provide more accurate temperature information for components such as fuel filters that are installed at the periphery of the vehicle, compared to other temperature sensors that measure oil temperatures or other temperatures of centrally located vehicle components. In some embodiments, the vehicle is automatically started when the temperature indicated by the fuel temperature sensor falls below a startup temperature threshold value, and is automatically stopped after a predetermined time period or after the temperature reaches a shutdown temperature threshold value.

Methods and systems are provided for controlling operation of an engine of a vehicle to supply power to a power box that in turn supplies power to loads external to the vehicle. In one example, a method comprises, responsive to a request by an operator to operate an engine to power one or more loads external to the vehicle, monitoring an engine temperature and issuing an alert requesting the operator to take mitigating action to reduce the engine temperature when the engine temperature reaches a threshold temperature, and controlling a cooling fan as a function of whether or not the mitigating action is taken. In this way, fuel economy may be improved and power supply to power external loads may be optimized.