Cars that have engines powered by petrol or diesel work because of a thing called internal combustion. Internal combustion works by creating and using a chemical reaction to move the engine’s mechanical parts. This chemical reaction is caused by a spark from the spark plug igniting the fuel which becomes very flammable when mixed with oxygen, thus causing an expansion of high temperatures and pressure that applies direct force to the engine components. This pressure effectively turns the chemical energy into mechanical energy. This is why an air filter is such an integral part of any car, since it has the task of cleaning the air that the engine takes in.
If the air in the car’s engine is not clean, but rather filled with dirt, dust and debris, then it will have a vastly decreased chance of allowing the fuel to ignite, not to mention the fact that such substances can potentially cause damage or at least some wear and tear to a few engine parts such as the cylinders and the piston rings. At best, this can result in decreased performance, and at worst in deterioration of the engine’s components.
This means that an air filter on a standard car in optimal conditions is an important item, however if you live in a place like Australia where it would be much stranger to not get dirt into your engine, and if you drive a pick up like the Toyota Hilux, then a proper Hilux air filter is one of the most integral components for your car.
Since the Hilux air filter plays such an integral role in everything the car does, then you would naturally want to maintain it as best as possible. But there really isn’t a way or a reason to do that. An air filters sole job is to absorb materials from the air which cannot be separated from it afterwards. Meaning that the only way to tell if an air filter is doing its job is if it collects enough materials that it cannot properly do it anymore.
But seeing as how a filter is so important and since it can’t be properly cleaned out the only option left is to replace it all together. Now, while all cars need the air filter to be regularly replaced, there isn’t a standard length of time after which this is done since the state of the filter has little to do with how much time has passed or distance travelled, but is rather much more influenced by the conditions of the roads and how often it is forced to try and clear away larger quantities of dust. However, as mentioned before, a good way to tell when it’s time to get a new one is if the current one is having problems and causing performance issues in the car.