A hollow filter element, including: a filter medium for filtering a fluid; wherein the filter element is a conical-oval rounded filter element; wherein the filter medium circumferentially surrounds an interior flow space of the filter element, wherein the filter medium circumferentially encloses around an element axis such that filter medium at least in one direction radial to the element axis is smaller on a first of the end sides of the filter medium than on a second of the end sides of the filter medium; wherein the filter medium has a first end body arranged at least on the smaller end side; wherein the first end body has at least one leveling element in the at least one direction of the smaller extent with respect to the element axis in a radially outer segment with respect to the element axis.

A hollow filter element, including: a filter medium for filtering a fluid; wherein the filter element is a conical-oval rounded filter element; wherein the filter medium circumferentially surrounds an interior flow space of the filter element, wherein the filter medium circumferentially encloses around an element axis such that filter medium at least in one direction radial to the element axis is smaller on a first of the end sides of the filter medium than on a second of the end sides of the filter medium; wherein the filter medium has a first end body arranged at least on the smaller end side; wherein the first end body has at least one leveling element in the at least one direction of the smaller extent with respect to the element axis in a radially outer segment with respect to the element axis.

A crawled vehicle comprising: an internal combustion engine; an engine compartment wherein the internal combustion engine is housed; an air inlet opening to catch air from the outside of the crawled vehicle; a first channel, for cold air, connected and fed by the air inlet opening with air coming from outside the crawled vehicle; a second channel to be fed with hot air coming from the internal combustion engine; a third channel for air, coupled to the internal combustion engine to feed the internal combustion engine with air; an air filter arranged along the third channel and upstream of the internal combustion engine; a connection element connected to the first channel, to the second channel and third channel; and an air adjusting device to adjust the air temperature in the third channel and comprising a shutter coupled to the first channel and/or to the second channel and/or to the connection element; and a control device controlling a position of the shutter to adjust the temperature of the air entering the third channel.

An air purifying prompting system includes an air purifying system and a prompting server wirelessly communicated with the air purifying system. The air purifying system includes an air purifying processor, an air filter communicating with the air purifying processor, a positioning module for positioning the air purifying system, and an air quality sensor for detecting air quality around the air purifying system, wherein the prompting server is arranged to generate an air filter usage time data. The air filter usage time is used to activate generation of air filter prompting signals to the air purifying system.

An air purifying prompting system includes an air purifying system and a prompting server wirelessly communicated with the air purifying system. The air purifying system includes an air purifying processor, an air filter communicating with the air purifying processor, a positioning module for positioning the air purifying system, and an air quality sensor for detecting air quality around the air purifying system, wherein the prompting server is arranged to generate an air filter usage time data. The air filter usage time is used to activate generation of air filter prompting signals to the air purifying system.

A system for tracking oil health of an engine includes an electronic fuel injection system which includes an electronic governor control unit. The electronic governor control unit is programmed to track engine parameters, calculate oil health based on the tracked engine parameters and on engine type, and display an indication of oil health.

Methods and systems are provided for diagnostics of an exhaust tuning valve during vehicle-off conditions. In one example, the engine may be reverse rotated, unfueled while the position of the exhaust is varied and an intake air flow is estimated at each position of the exhaust tuning valve. The exhaust tuning valve may be diagnosed based on a change in air flow with the variation in the position of the exhaust tuning valve.

Methods and systems are provided for diagnostics of an exhaust tuning valve during vehicle-off conditions. In one example, the engine may be reverse rotated, unfueled while the position of the exhaust is varied and an intake air flow is estimated at each position of the exhaust tuning valve. The exhaust tuning valve may be diagnosed based on a change in air flow with the variation in the position of the exhaust tuning valve.

Methods and systems are provided for reliably prognosing a vehicle component, such as a vehicle battery or an intake air filter. A state of degradation of the component is recursively predicted by updating, based on a sensed vehicle operating parameter, a previously estimated state of degradation of the component, the parameter selected based on the component being diagnosed, as well as based on past driving history and future driving predictions. The predicted state of degradation is then converted into an estimate of time or distance remaining before the component needs to serviced, and displayed to the vehicle operator.

Methods and systems are provided for reliably prognosing a vehicle component, such as a vehicle battery or an intake air filter. A state of degradation of the component is recursively predicted by updating, based on a sensed vehicle operating parameter, a previously estimated state of degradation of the component, the parameter selected based on the component being diagnosed, as well as based on past driving history and future driving predictions. The predicted state of degradation is then converted into an estimate of time or distance remaining before the component needs to serviced, and displayed to the vehicle operator.