Why A Tune-Up Is No Longer Relevant For Today’s Cars

Millions of consumers still consider a periodic tune-up to be an essential part of taking care of their vehicles. But the term is often misused, misunderstood, and for all but a few purposes, irrelevant. Adding to the confusion, many auto repair shops aggressively promote their tune-up services.

In this article, we’ll describe what a tune-up has traditionally involved, and explain why it means something entirely different today. The reason is due to the evolution of automotive design. You’ll also learn how a tune-up entails different maintenance items from one repair shop to another. Many people are unaware of the checks performed on their cars, even though they are spending hundreds of dollars for the service.

What Is The Mechanic Adjusting?

Years ago, automobiles relied on components that were completely mechanical. When cars and trucks rolled off the factory floor, their parts were calibrated to help their engines perform at maximum efficiency. As time passed, however, the mechanical parts would slowly lose their original settings. As a result, the engine would begin to operate with lower fuel efficiency and power. The components needed to be adjusted in order to return the assembly to its previous peak performance.

Today’s vehicles are designed with electronic components that are influenced by a computer. There is no carburetor to adjust. Nor is there a need to make adjustments to mechanical parts for the purpose of improving ignition timing or idle speed. The computer handles these and other functions. With this in mind, what is the mechanic adjusting when you take your car into the shop for a “tune-up?”

A Tune-Up Can Mean Different Things

Here, the confusion worsens. Nearly all repair shops will replace your spark plugs as part of a modern tune-up. Some shops will do little more. Others will replace your air and fuel filters, test the plug wires for resistance, and visually inspect them for damage to their insulation. Still other repair garages will take the service a step further, checking the PCV (positive crankcase ventilation) valve, oil level, battery output, and treadwear on your tires. Some will also check the coolant level as well as the condition of your distributor cap and rotor.

Note that none of the parts described above technically require adjustments, or “tuning up.” They can, however, provide clues to other problems that may warrant repairs. For example, a cupped wear pattern on your front tires may suggest a problem in your car’s suspension. A low oil level might imply that your engine is burning oil. A low coolant level may indicate a failing head gasket. Even though the term “tune-up” is a misnomer, the service itself can be valuable depending on the maintenance items that are included.

The Cost Of Having Your Vehicle “Tuned Up”

Since the cost of any type of automotive repair is dictated by the parts involved and the amount of labor required, the cost for a tune-up varies. If the shop intends to do little more than replace your spark plugs, plan to pay up to $150. Keep in mind, this job can be accomplished at home for the cost of the plugs themselves (less than $40 for a pack of four spark plugs).

On the other hand, if the mechanic replaces your filters, checks your PCV valve, distributor cap, and rotor, and rotate your tires, expect to pay $250 or more. A comprehensive service will also include checking the ignition timing, engine compression, idle speed, exhaust emissions, and belts and hoses. If problems are discovered, however, they cannot be resolved by making adjustments. Further repairs or parts replacements are usually necessary.

As a side note, it is also important to periodically check your fuel injectors and oxygen sensors. The former can become dirty as deposits and debris fill the nozzles, preventing fuel from reaching the combustion chambers. The latter can begin to fail on high-mileage cars, causing an increase in exhaust emissions. Neither are included in a typical tune-up, but remain important to the efficient operation of your engine.