Scheduled services are incredibly important in order to keep your vehicle up and running at peak performance. Manufacturer-recommended services are usually pertinent to keeping a manufacturer-backed warranty intact as well. While each car has a different maintenance schedule, which can be found in the owner's manual, there's a rough outline you can follow to get the gist of scheduled service.
The 15,000-mile mark is when most vehicles are in need of their first full service outside of an oil change and tire rotation. The first round of scheduled service isn't too costly but it could still run a few hundred dollars. When all is said and done, you should have fresh oil, a new air filter, rotated tires, and a full inspection of the braking and cooling systems.
The 30,000-mile mark is a bit more costly as it includes all the items from the original 15,000-mile service plus a few others. In addition to the previous items, this scheduled service should include fresh transmission fluid, a new fuel filter, and a thorough inspection of key systems.
Some mechanics might recommend changing your spark plugs at 30,000 miles. This is unnecessary for most vehicles depending on the spark plug quality. Some vehicles may not even need fresh transmission fluid either.
The 45,000-mile mark should include all of the services of the 15,000 and 30,000 marks. The only addition is new transmission fluid if you chose to forego that service at 30,000 miles.
The 60,000-mile mark should include all services performed during the 30,000-mile service. You'll also want to inspect and replace any belts, hoses, and valves that are wearing quickly. Some vehicles may need new spark plugs as well, depending on the type.
The 100,000-mile mark brings a full round of service. It should include all of the previous items as well as several long-lasting items, such as some spark plugs and orange coolant. If the car is still operating at this point, odds are you've already got the hang of the scheduled service thing.