What Is a Tune-Up?

Mia Bevacqua
July 5, 2018


Engine tune-ups used to be extremely involved and time-consuming. The job required changing ignition points, adjusting the carburetor — the list was endless. To make things worse, it had to be done regularly to keep a car running right.

Fast-forward 30 years and tune-ups are almost nonexistent. Advanced electronics have replaced the mechanical components that required constant tweaking. For drivers and mechanics both, life is much simpler.

So, what is a tune-up these days? Typically, it's now part of the routine scheduled maintenance, often due every 30,000 miles or so. It usually involves changing the spark plus or engine air filter, and maybe cleaning the throttle body, if it has carbon buildup.

What’s involved with a modern tune-up

Most of the time, when a vehicle made in the past couple decades isn’t running right, the check engine light pops up. But while the human factor has been mostly eliminated, today’s vehicles still have a few components that need tuning up.

Spark plugs

All vehicles — other than diesels and pure-electrics — still have spark plugs. But many of the related components have disappeared. Distributors, ignition caps and (in most cases) spark plug wires have given way to individual ignition coil packs designed to last the life of the vehicle.

Spark plugs themselves have changed, too. While traditional, copper plugs used to last 30,000 miles, modern platinum and iridium plugs typically last around 100,000 miles.

Air filter

Internal combustion engines require clean oxygen, so air filters are still around. And they haven’t changed much, either. Today’s air filters typically have a service life of around 30,000 miles.

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Tune-up components that have gone away

Car owners haven’t had to worry about carburetors for over 30 years. Distributors are also gone. But even just 10 years ago, there was much more to a tune-up than there is today. The following components have been done away with in the last decade or so.

Cap, rotor and spark plug wires

As mentioned earlier, instead of distributors, cars now have individual ignition coil packs that sit on top of the spark plugs. These units are controlled directly by the engine’s computer. As a result, there’s no need for a cap, rotor or even spark plug wires. Since there’s no distributor, the ignition timing doesn’t have to be adjusted, either. It’s all controlled by the engine’s computer.

Fuel filter

Vehicles used to be designed so that gasoline was routed to the engine, through the fuel filter. Any fuel in excess of what was needed was routed back to the gas tank. New vehicles have a different layout, referred to as a “return-less” fuel system. As the name implies, with this setup, there’s no return line. A computer commands the fuel pump to deliver the correct amount of gas to the engine every time. As a result, there’s no separate fuel filter. There’s only an in-tank strainer designed to last the life of the vehicle.

Timing belt

In the past, Asian and European vehicles almost always had a timing belt. Because it would stretch, periodic replacement was required. Changing it was often a harrowing ordeal that could cause extensive engine damage if not done right. Fortunately, today’s engines have systems like variable valve timing that require a timing chain. Unlike belts, these parts do not need routine service.

Other maintenance items  

A tune-up typically refers to the periodic service of engine performance components. But this isn’t the same as routine maintenance. Modern vehicles still have plenty of items that should be taken care of on a regular basis.


There’s no doing away with the myriad of fluids cars require. Like their ancestors, today’s vehicles use engine oil, transmission fluid and coolant. Although many of these items now last longer, they still require routine replacement. Some cars are now moving toward lifetime fluids, though, so even that may change.

Cabin filters

The cabin air filter is one item that’s been added to the maintenance roster. These components started showing up on vehicles about 10 years ago. They’re designed to purify cabin air so occupants can breathe easier. While they’re not critical to engine performance, they can clog and create a musty smell and poor airflow through the dashboard vents.

Mia Bevacqua

About the Author

Mia Bevacqua is an automotive expert with ASE Master, L1, L2 and L3 Advanced Level Specialist certification. With 13-plus years of experience in the field, she applies her skills toward writing, consulting and automotive software engineering.

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