The term tune-up dates to the time when Henry Ford was working on his first automobile prototype.
In Ford's simple ignition system, there was one ignition coil for each spark plug. If there were four
spark plugs, there were four ignition coils, which needed to be adjusted to provide the same spark
intensity for a better idle and acceleration. As these ignition coils worked, they made a buzzing sound,
and when they were adjusted properly, they all buzzed in "tune". The term "tune-up" stuck and became
associated with replacing spark plugs and correcting rough idle problems effecting engine performance.
Once the distributor was developed, the term "tune-up" had no meaning, but the consumer who was used to
hearing this term around a garage still associated poor performance and running quality with the need for
a "tune-up".
Today's automobiles do not require "tune-ups". The term indicates the need for routine maintenance and
should not be associated with poor performance. Automobile manufacturers have developed recommended routine
maintenance schedules, which specify intervals for replacing spark plugs, PCV valves, fuel filters, etc.
These schedules also specify intervals for checking and adjusting ignition timing, idle speed and other
items related to engine operation, as well as emission-control related devices.
If your vehicle experiences any operating or performance problems between maintenance intervals, that
specific problem should be addressed by performing an engine analysis to isolate that particular problem.