Although many drivers are unaware of the fact, weather can have a profound effect on vehicle system performance. The presence of heat, humidity, wind, salinity and other atmospheric conditions can negatively or positively affect numerous vehicle systems.
For example, in hybrid vehicles or battery electric vehicles, the presence of excess heat or cold can greatly impact battery efficiency and performance. In fuel-propelled vehicles, combustion in the engine can be affected by humidity. In vehicles equipped with solar regeneration capacity, cloud cover can diminish this capacity. Wind can produce resistance to driving, diminishing fuel efficiency of almost any type of vehicle. Extreme temperatures can also encourage a greater usage of vehicle HVAC systems, draining batteries and/or fuel in an attempt to maintain a comfortable cabin temperature within the vehicle.
Weather forecasts have a tendency to be moderately accurate at best, and rarely can they accurately predict specific conditions at a particular location and future time. If the driver of a vehicle is located in the immediate proximity of a weather station, then the accuracy of the report may be almost spot on, but the further a driver moves from the point where the conditions were actually measured, the less precise the predictions or measurements are apt to be, and they are more likely to be a generalization of observed weather at locations where measurements are taken.
Because weather data is often imprecise and/or varies with travel, it is difficult to appropriately modify changeable vehicle systems to adapt to localized weather. Further, it is difficult to predictively adapt to weather, since any advance calibration may simply be done off of a nominal measurement or prediction of weather. In at least one example, a persistence forecast may be used for adjustment, but this may be highly inaccurate.