- On five of our own 2026 tickets, a full set of spark plugs came to $255 to $295 with parts and labor.
- Four, six and eight cylinder engines all landed in that range. Most were written at one hour of labor.
- The plugs ran $15 to $26 each on those tickets. Kelley Blue Book says most plugs cost under $10, and the best ones up to $25.
- Two things blow up the bill. New coils added $491 on one V6 estimate. A seized plug that took the threads with it pushed one Corolla to $614.
- AAA puts the national range at $100 to $250 for a 4 cylinder and up to $500 or more for a V8.
$255 to $295. That's what a full set of new spark plugs came to on five of our own tickets written between August and October 2026, parts and labor together. Those were a Hyundai Kona, a Nissan Altima, a Nissan Maxima, a Toyota 4Runner and a Chevy Silverado.
That spread is tight for a reason. The plugs are cheap. What you pay for is the time to reach them.
We work on cars all over Hemet, San Jacinto and the rest of Riverside County, at the shop and in driveways. So this guide uses our own numbers first, then checks them against AAA and Kelley Blue Book.
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What Our 2026 Tickets Show
These are real Supercanic tickets with spark plug work. Labor is at our posted $150 an hour.
| Car | Engine | Labor | Plugs | Total |
|---|---|---|---|---|
| 2021 Hyundai Kona | 4 cylinder | 1 hour, $150 | $105 for 4 iridium | $255, paid |
| 2010 Nissan Maxima | V6 | 1 hour, $150 | $110.52 for 6 | $260.52 |
| Toyota 4Runner | V6 | 1 hour, $150 | $131.28 for 6 | $281.28 |
| 2017 Nissan Altima | 4 cylinder | 1.5 hours, $225 | $60 for 4 | $285 |
| 2021 Chevy Silverado | V8 | 1 hour, $150 | $141.04 for 8 | $291.04 |
| 2013 Toyota Corolla | 4 cylinder, seized plug | 3 hours, $450 | $74.92 for 4, plus an $89 thread insert kit | $613.92 |
The Kona was a paid job. The rest are written estimates, the price the owner saw before any work. Tax is not included.
Five Normal Jobs, and One That Went Wrong
Supercanic tickets, August 29 to October 16, 2026. Parts and labor, before tax.
We left out tickets where the plugs rode along on a bigger job, like a head gasket or an engine swap. Those don't tell you what a plug job costs.
Why a V8 Did Not Cost Double
You'd think eight plugs cost twice as much as four. On our tickets, they didn't.
The Silverado's eight plugs came to $291. The Kona's four came to $255. The gap was the parts, not the labor. Both were written at one hour.
On most trucks and V6 cars, the plugs sit right under the coils, in easy reach. Pull the coil, pull the plug, done. Cylinder count adds parts and a few minutes. Access is what adds hours.
AAA sees it the same way at a national level. It puts a 4 cylinder at $100 to $250, a V6 at $150 to $350 and a V8 at $200 to $500 or more. The top of each range is the engine where something big has to come off first.
Our 4 cylinder jobs land just past the top of AAA's range. That's the full hour and the iridium plugs. A plug job on a simple engine still takes real time to do right, and we don't rush torque on an aluminum head to shave 20 minutes.
What the Plugs Themselves Cost
Kelley Blue Book says most spark plugs cost under $10 each. Platinum and iridium plugs can run as much as $25. A full set runs $16 to $100, based on the type and how many cylinders you have.
On our tickets, plugs ran $15 to $26 each. That's because most modern engines call for iridium.
| Plug Type | Price per Plug | How Long It Lasts |
|---|---|---|
| Standard (nickel) | $2 to $5 | 20,000 to 30,000 miles |
| Single platinum | $6 to $12 | Up to 60,000 miles |
| Double platinum | $10 to $18 | 60,000 to 100,000 miles |
| Single iridium | $12 to $20 | Up to 100,000 miles |
| Double iridium | $16 to $25 | Up to 120,000 miles |
The prices and life spans above come from AAA's plug type table.
A tip that saves money. Buy the plug your engine came with. A cheap plug in an engine built for iridium means you pay for the labor again much sooner. And a pricey plug in an old engine built for standard plugs buys you nothing.
One more thing on names. People call standard plugs "copper." NGK says that's wrong. The tip is a nickel alloy. Nearly all of its plugs, iridium too, have a copper core inside to carry heat away.
When the Price Jumps
Most plug jobs are boring. These are the ones that aren't.
New coils. On the 2010 Maxima, the plugs were $260.52. Six new coil packs added 1.5 hours and $266.28 in parts, another $491.28. Coils are worth doing together only when one is failing or the miles are high. A good coil can go back on.
A seized or spinning plug. The 2013 Corolla had a plug that would not come out clean. The estimate was three hours to get it out and fix the threads in the head with an insert kit. That turned a $285 job into $613.92. It still beat a new cylinder head.
A plug that blew out. Some engines are known for it. On a 1997 Ford F-150 in Beaumont, a plug backed out and took the aluminum threads with it. We fixed it in place without pulling the head.
Plug wires. Older engines with wires should get new ones with the plugs, Kelley Blue Book says. That adds parts, and a little time.
A misfire nobody has traced. If the check engine light is on, a plug job may not fix it. On a 2006 Grand Caravan, we tested first and found the plugs were fouling out. Testing first is cheaper than guessing with parts.
How Often to Change Them
Your owner's manual has the real number for your engine. As a guide, Kelley Blue Book says the old rule was every 30,000 miles. Extended life plugs can go as far as 100,000.
Most of the time you don't need a special trip. Plugs come up at a scheduled service.
Don't wait for the miles if you notice these. AAA lists them as signs plugs are due.
- Hard starts, worst on a cold morning.
- A rough idle or a shake at a stop.
- A misfire that may turn on the check engine light. Our check engine light guide covers what to do next.
- Worse gas mileage than you used to get.
- Slow or stumbling when you step on the gas.
Doing It Yourself
On an engine with the plugs on top, this is a fair DIY job. Parts run $16 to $100. But a few rules matter.
Torque matters most. NGK says to always follow the torque spec. Too loose and the plug can't shed heat. Too tight and you can damage the threads or the plug.
Follow the plug maker on anti-seize. NGK ships its plugs dry and says not to use anti-seize on them. It says anti-seize can change torque by up to 20 percent. Other brands and engines can differ, so read the box and the service info.
Be gentle with the gap. Most NGK plugs come pre-gapped. If you must adjust one, NGK says to move it no more than 0.008 inch from the factory gap, and never pry on the fine wire tip.
Let it cool. Pulling plugs out of a hot aluminum head is how threads get hurt.
If a plug fights you on the way out, stop. Forcing it is how a $285 job becomes a $614 job.
What a Fair Estimate Looks Like
In California, a repair shop has to give you a written estimate before it makes any repairs. It can't charge more than that estimate without your OK. The Los Angeles County consumer office spells that out, and the Bureau of Automotive Repair takes complaints at (800) 952-5210.
A good plug estimate shows four things.
- How many plugs, and what type.
- The labor hours and the rate.
- Whether coils, wires or intake parts are in the price.
- What happens if a plug is seized, so you are not surprised.
If you're ready to compare, see what our engine repair work covers, or book diagnostics first if the engine is misfiring.
Supercanic tip. Text us your year, make, model and engine. In Riverside County, call or text (951) 904-2477. We'll send a written estimate at our posted $150 rate before any work starts, and we can do most plug jobs in your driveway.
Quick Hits
- How much does it cost to replace spark plugs?
- On our 2026 tickets, a full set came to $255 to $295 with parts and labor. AAA puts the national range at $100 to $250 for a 4 cylinder and up to $500 or more for a V8.
- Are more expensive spark plugs worth it?
- Only when your engine calls for them. Use the type your engine came with. Iridium lasts longer, but it buys nothing in an engine built for standard plugs.
- Can I drive with bad spark plugs?
- For a short time, but it gets worse. Worn plugs cause misfires, hard starts and poor mileage. If the check engine light is flashing, get it checked before you drive far.
- What are the first signs that my spark plugs are bad?
- Hard starts, a rough idle, a stumble when you step on the gas and worse gas mileage. A misfire can also turn on the check engine light.
- What kills spark plugs quickly?
- An engine that fouls them, like the 2006 Caravan we fixed. Wrong torque hurts them too. NGK warns that over torque can stretch the plug and damage the threads.
- Should I replace ignition coils with spark plugs?
- Only if a coil is failing or the miles are high. On one of our V6 estimates, six new coils added $491.28. A good coil can go back on.
What We Read
AAA Automotive, What Is the Average Spark Plug Replacement Cost?
Kelley Blue Book, Spark Plug Replacement Prices and Cost Estimates
NGK Spark Plugs, 5 Things You Should Know About Spark Plugs
Los Angeles County Department of Consumer and Business Affairs, Car Repairs March 4, 2024
Supercanic Shop Desk estimates and invoices with spark plug work, August 29 to October 16, 2026
Engine Running Rough?
Get a written plug estimate before you spend a dime. We cover Hemet, San Jacinto and the rest of Riverside County.
