Skip the auto shop - Our mechanics make house calls

How Often Should Spark Plugs Be Replaced?

Spark Plugs

While your engine runs on gasoline, it also requires electricity. It’s needed to operate most of your accessories, but is also required to make the engine run. Spark plugs connect to wires that lead to the ignition system. Electricity is created by the alternator and sent to the plugs, which create arcs of electricity. This is what ignites the fuel in your engine’s cylinders, creating the combustion that pushes the pistons down and actually turns the engine. Spark plugs are vital parts of your car.

Spark plug wear

Like most other components of your engine, spark plugs wear down over time. The primary type of wear here is with the electrode. If you look at a spark plug, you’ll notice one end is narrow and tapered – this is where the wire connects to it. The other end is bulbous, with a small metal rod coming out of the center, and a metal hook to one side. That center rod is the electrode – electricity arcs from that to the hook.

Through normal use, the electrode on each spark plug does wear down. Eventually, it becomes so worn that it doesn’t create as much (or any) electric arc, which has a direct and immediate effect on your engine operation.

When to replace spark plugs

If you check your owner’s manual, you’ll probably find that your automaker recommends you replace your spark plugs roughly every 30,000 miles. That’s fine if you’re using stock spark plugs. However, the actual timing of replacement will vary depending on other factors.

  • High Performance: If you have high performance spark plugs, it’s possible that you will need to replace them more often, as the electrode can wear down faster.

  • Long Life: Some spark plugs are made to have a longer life. Their electrodes do not wear down as quickly, meaning that you won’t need to replace them as frequently. Look for plugs made from iridium or platinum for the longest life (copper has the shortest lifespan – generally about 20,000 miles).

  • Oil Leaks: When you pull a spark plug out of the engine, the base should be relatively clean. If there is oil present, it means there’s a leak. Not only does that mean you’ll need to replace a blown seal, but it means your spark plugs will need to be changed more frequently because of contamination.

  • High Revs: If you regularly “put your car through its paces,” you’ll put additional wear and tear on your spark plugs, meaning that you’ll need to replace them more often. Drivers with a lighter foot will enjoy longer life from their plugs.

If your engine seems to be running rough, or skipping, chances are good that it’s time to have your plugs replaced. Other symptoms can include rough idling and stalling.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...
Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...


Related questions

Q: Ford Explorer not starting. Low miles.

In order for an engine to start it needs a charged battery, a working starter, properly functioning ignition switch and ignition system, a fuel system that is working correctly, good wiring and connections throughout, and a free rotating engine (unseized)....

Q: Spark plug not working

A cylinder #6 misfire doesn't necessarily mean the plug is bad. There are many other things that could cause a single cylinder misfire, from a faulty fuel injector to an engine mechanical problem. Anything that causes incomplete or abnormal combustion...

Q: My car makes a very odd beeping noise, what gives?

Hi there. This is most likely a service reminder indicator chiming. Take note of any messages on the display panel. It could also be the seat belt reminder chiming. This could be due to the belt being unfastened or the...