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.