Sometimes it seems like there are a bazillion parts in a car, and each of them just waits until the worst possible moment to fail. But car parts have their own timetables. If you know which parts need regular maintenance and when, you will avoid a lot of problems, avoid being taken advantage of, and get the most value out of your automobile.
The list below sets out common general maintenance intervals for car parts (your user manual will give you more precise intervals for your car).
Notice that some intervals are specified in miles driven and some are specified in time. Soft parts and some fluids will start to break down whether you use them or not, but hard parts wear out from use. The list does not include more frequently changed items like air filters and brakes because their lifespan has more to do with the conditions under which they are used than either time or mileage. If you drive down from the Mesa or from Santa Ynez, you will be harder on brakes than if you spend all your time in the flats.