What Is a Tune-Up on a Modern Car

Regardless of what vehicle you drive or how well you drive it, your car won’t last very long without regular maintenance and the occasional tune-up. Over time, the definition of a car tune-up has changed, but why do cars need to be “tuned up” in the first place? The simple answer is that engine parts eventually wear out. But it’s more than that.

Even new engines vary slightly in how well they convert the potential energy in gasoline or diesel fuel into motive force to move the vehicle. For every revolution, the delivery of air, fuel, and spark needs to be timed precisely. Even slight differences in air flow turbulence and variations in fuel flow can affect how well the engine runs. A vehicle’s initial factory settings ensure a short period of ideal operation. Over time, through repeated heating and cooling cycles and hundreds of thousands of revolutions, spark plugs vaporize molecule by molecule, fuel deposits gradually form, and spark energy can weaken, taking a toll on engine performance and efficiency.


Basically, a tune-up is a series of maintenance steps to return an engine to its ideal operating state. Whether you’re towing, hauling, cruising, or launching down a quarter-mile track, a tuned engine will get you to your destination powerfully and efficiently.

Years ago, getting a tune-up involved multiple steps, some of which required especially skillful hands. Carburetted engines needed to be adjusted occasionally to account for fuel quality, altitude changes, and wear. Copper spark plugs and spark plug wires needed to be replaced about every 25,000 km, and other ignition system parts, such as the ignition coil, distributor cap and rotor, breaker points and condenser, and base ignition timing had to be replaced or adjusted.

Some things haven’t changed at all, such as replacing the air filter, spark plugs, and PCV valve. Platinum and iridium spark plugs tend to last up to 160,000 km, depending on engine type, and modern coil-on-plug ignition systems have eliminated spark plugs wires, and distributor parts from the equation. Depending on the conditions in which you drive, a new air filter may be recommended every 50,000 km and a new PCV valve every 100,000 km. Every 50,000 to 75,000 km, cleaning the throttle body, idle air control value, and intake valve are still recommended as well.

Thanks to better engine manufacturing, higher lubricant quality, and computer controls, modern engines don’t require nearly as much tuning up as their predecessors. Engine controllers adjust ignition timing and fuel injector timing on the fly, without a technician’s intervention. Because engine controls are software-based, certain adjustments may be made without having to replace any parts. Some engine problems may be solved by a software upgrade, which may require a visit to the dealership, but may sometimes be accomplished remotely, just like smartphone software updates.


Usually, your car lets you know it needs a tune-up by the way it’s running. If you’re experiencing poor fuel economy, rough idling, or the engine won’t start, your car might need a tune-up. On computer-controlled engines, especially post-1996 OBD2 engine controllers, the check engine light might be your only indication of a problem. Either way, visiting a trusted local mechanic will get your engine back to peak performance.

Check out the fuel system cleaning services available at any of our 600 NAPA AUTOPRO shops for routine maintenance and repairs. For more information on car tune-ups, chat with a knowledgeable expert at your local NAPA AUTOPRO Service Centre.

Benjamin Jerew