The frequency of changing oil depends on the age of the car. Due to the addition of computers as the central feature of your vehicle's function, newer vehicles do not require the same form and frequency of maintenance as older cars do every 10,000 to 12,000 miles. A tune up is an effective service performed on modern cars that typically involves changing the oil, replacing the engine air filter, replacing the spark plugs, flush services, and possibly a few other things as well. A tune up is typically advised when a car’s performance deteriorates or when the spark plugs need to be replaced according to the maintenance schedule.For older or high mileage vehicles, additional tuneup services might include replacing the front oxygen sensor when the car gets poor gas mileage, replacing the fuel filter, and replacing the throttle body and the timing body.